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    Bad guide, even worse mod LittleLebowski's Avatar
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    USAMU reloading article series

    ***This was posted on Facebook over a period of time and I lucked into a collated document containing the text. This post will change over time as I have time to edit.***

    Getting Started in Handloading, Part 1

    Here at the USAMU Handloading Shop, we receive inquiries from shooters at many skill levels. One of the most frequent questions we are asked is, “What equipment do you recommend I buy, to start handloading?”

    Often, the correspondent will be focused on producing ammo in quantity, and a big concern is whether to begin with a single-stage vs. a progressive press. However, there is one critical item that often gets overlooked as folks talk about the especially interesting topics such as reloading die brands and types, scale types and brands, etc. And, what might that item be?

    “When all else fails, read the WHAT??” Yes, we recommend those new to handloading actually begin with reading the early chapters of 1 or, preferably, 2 quality handloading manuals. They contain copious information on basic*handloading*safety, how to choose and use components, and how to recognize and avoid potentially dangerous conditions. Of course, they also do a fine job of teaching new loaders the correct methods of adjusting dies, determining safe loads, improving accuracy, etc.

    “So, which manuals do you recommend?” As a government entity, we aren’t able to make specific brand-name recommendations as such. However, recent manuals from the major bullet and powder manufacturers, especially those who emphasize accuracy and match-type bullets, are generally a wise choice. (Note from LittleLebowski, the most current and therefore most desirable reloading manual is the Lyman 50th Editon)

    Handloaders will, over time, come to prefer one or two maker’s manuals over others for various reasons. Asking a friend who’s already an experienced loader which manuals they recommend is a good start. Borrowing 1 or several to read before purchasing, is another. This is a good way to both save money and get a feel for the variety of component types and data that are available. Comparing differences in data from different manuals in the same caliber, with the same powder and bullet weight can be an eye-opener. It is also a wise step in researching any loading project before one begins – and the reasons for the differences are fully explained in the manuals!


    Beginning Handloading, Part 2

    Welcome to another edition of the USAMU Handloading Shop’s weekly “Handloading Hump Day!” We receive frequent requests for gear recommendations from new handloaders. Thus, we are running a short series on basic equipment for the beginner, to help them safely get high-quality results with good (not necessarily expensive) equipment.

    For those who missed Part 1, our first recommendation is one that, surprisingly, many handloaders skip – even long-time shooters. We recommend carefully reading the safety and technique information contained in 1 or 2 quality handloading manuals, as we outlined on 17 June 2015. Doing so helps beginners recognize and avoid many potential pitfalls and shortens the learning curve tremendously.

    Our second recommendation is to buy proven, high-quality equipment. It should have a reputation for great durability, good ergonomics and reasonable-to-excellent precision. In addition, ask fellow shooters which companies have a good reputation for support after the sale. Several of the better handloading companies set the bar very high.

    With the better ones, it’s common to call to order small replacement parts and receive them at no charge in the mail immediately thereafter. Other companies don’t enjoy such a sterling reputation. Often, these focus on cheap equipment made with low-quality materials, aimed at those to whom cost is THE prime consideration.

    Good quality equipment not only leads to less frustration, faster production, better results and less misery – it is also an excellent investment. Certain companies’ products sell virtually instantly on the “used” market and retain high re-sale value. Other gear from less well-regarded companies is much more difficult to sell. Moreover, it brings far less of its original purchase price, if it can be sold at all.

    Ask veteran handloaders – preferably those who are still very active in the shooting sports -- which equipment they prefer, and why. After getting specific recommendations, search for reviews of that equipment, as well as possible alternates and newer designs. Learn the steps of operating the various options, and evaluate them for efficiency, effort and precision. A little research can pay big dividends, here!

    A prime example of this would be case trimmers. Trimming rifle brass is one of the universally least-enjoyed handloading chores, so it really matters which trimmer one buys.

    A fellow who loads maybe 100-200 rounds a year will likely be satisfied with his 40-year-old case trimmer. And, why not? Although of obsolete design, its’ dull blades and very inefficient case holder work well enough for his needs. He never experiences the blisters, hand cramps and general pain that a competitive shooter attempting volume loading on such equipment will.

    As he’s had his gear for many years, he may have felt no need to improve, upgrade or even learn about better models over time. This occurs despite massive improvements in certain areas (especially case trimmers and case sizing lubricants). Therefore, while his advice may be perfectly valid, it may not be the most comprehensive or up-to-date.

    Competitive shooters who’ve been in the game and compete successfully (or at least competently!) are often a great source of extensive, first-hand knowledge. Their recommendations include both what to buy, and almost more importantly, what to AVOID.

    In general, it’s better to buy good equipment once and cry once, than to buy inferior gear and then spend that money again, plus more, on better gear shortly thereafter.



    Beginning Handloading, Part 3


    Happy Handloading Hump-Day! As promised, this week we’ll address a question frequently asked by prospective handloaders. To wit: “Should I buy a single-stage press, or a progressive?” The best answer is almost Solomon-esque in both its’ wisdom and simplicity: “Get BOTH!” However, there is definitely more to the issue than that… read on!

    Many are the beginning handloaders who have asked a friend about their “setting up” a progressive press for them. The idea is that the newbie could then just feed in components and crank out buckets of practice ammo without needing to really learn much about handloading.

    Tempting though this might be, that’s simply not how it works. Such an approach might be ok if there were never a malfunction with either press or operator, but that’s unrealistic. Our hypothetical newbie would then lack the knowledge to problem-solve most situations. Worse yet, several different handloading operations would be occurring at different stations on the progressive press at the same time. It takes an experienced operator to keep track of, and truly understand the significance of, all those potential mini-problems. Loading without this experience is a recipe for potential disaster – such as a double powder charge (especially with pistol cartridges) dropped while the loader was attending to some other function, etc. Progressives are an animal unto themselves, and while they offer many benefits, they do take some getting used to – even by experienced handloaders!

    ILLUSTRATIVE HORROR STORY: Here, enter a 40-year veteran handloader who decided to jump onto the progressive bandwagon late in his career, having used only single-stage presses all his life. A High Master NRA Highpower Rifle competitor, he had no background in competitive pistol shooting, where historically most progressive presses are found. Experienced Action Pistol shooters have typically encountered multiple episodes in which shooters “skipped” a powder charge for some reason, leading to a squib round and a bullet possibly lodged in the bore. Thus, at matches, it’s reflexive for them to yell “STOP!” in unison if they see a shooter get a “click” vs. “bang,” and rack the slide to keep firing. This writer has personally seen several pistols saved in just such scenarios over the years.

    Our High Master set up a popular progressive press and began turning out .223 100-yd. practice ammo with abandon. He was using a moly-coated 52 gr. match bullet and an economical, fast-burning surplus powder that gave great accuracy. Once on the range, he began practicing strings of rapid-fire. All was well, until he heard “Click!” rather than “Boom”…

    Lacking the above experience or onlookers to halt him, he reflexively operated the charging handle on his expensive, custom NM AR15 Service Rifle, and the next trigger squeeze reportedly registered on seismographs over at least a 3-state radius. He sat, uninjured but bewildered, until the hail of expensive bits and pieces quit raining down around him. When the smoke cleared, he immediately cursed the horrid, evil, demonically-possessed progressive press for this, his first-ever reloading mishap.

    His $1400 NM upper was ruined, but thankfully, his $800 pre-ban lower (yes, it was back then…) and he had escaped injury. A forensic reconstruction revealed what likely happened:

    1. He’d skipped a powder charge in 1 case.

    1. Moly-coated bullets result in lower neck tension unless steps are taken to increase it vs. standard jacketed bullets.

    1. Upon firing the squib, the bullet was projected into the rifling throat, which likely wouldn’t have happened without the light neck tension.

    1. Upon firing the squib, the bullet was projected into the rifling throat, which likely wouldn’t have happened without the light neck tension.

    1. The cartridge chambered fully, the trigger was squeezed and… well, you know the rest.


    This tale is told not to discourage the use of progressive presses, but to emphasize the need to EASILY and IMMEDIATELY KNOW what is happening with the press at each station, every time the handle is cranked. Not to do so is, as they say, “bad ju-ju.” It illustrates why we at the USAMU Handloading Shop agree in recommending that new handloaders should begin with a single-stage press. Once one thoroughly learns the steps in each phase of handloading by repeated experience, then one will be qualified to move on to a progressive press. Quite beyond that, the single-stage press will REMAIN virtually indispensable for one’s entire handloading career, even after having purchased a progressive press (or two). There are endless small projects that are best handled on a single-stage press, and a poll of USAMU’s Handloading staff reveals that not one would willingly be without his single-stage press, despite owning at least 1 progressive.


    Beginning Handloading, Part 4:
    Progressive Press Features and Advantages


    Welcome back to the USAMU’s “Handloading Hump-Day!” Our staff would like to thank you all for your many kind thoughts and comments! We’re glad to be of service.

    Last week, we addressed single-stage vs. progressive presses for the beginning handloader, and made the experience-based case that beginners would be better served by starting on a single-stage press.

    [CAVEAT: while many progressive presses are seen in photos of our Handloading Shop, remember that ALL of our powder charges are weighed by hand. We do not use powder measures on our presses. Progressives at our shop are used for preparation of brass, priming, seating, etc., but not for fully-progressive loading. ]

    For those interested in progressives, we’ll examine different key features among the types and relate them to handloading processes. The first, and simplest, type is the manually-advanced progressive. The shellplate holds the several cartridges being processed with each stroke of the handle. On these, the loader must manually advance the shellplate after each handle stroke. While this obviously slows production vs. a press which cycles the shellplate automatically, this feature does have some advantages. (The disadvantages follow shortly.) No case is advanced to the next station until the operator deliberately does so – which is especially helpful for the new handloader. Problems that arise during loading can be diagnosed and fixed without fears of some “extra” process happening with cartridges at the other stations. NOTE: One way to positively prevent this phenomenon is to remove the cases from each press station when a problem emerges, before beginning diagnosis. Often, however, experienced loaders omit this step as a time-saving measure, being confident in their understanding of the loading process, machine and remedy.

    If all cartridge cases are left in place, the loader must monitor what’s happening at each station. For example, raising the press ram twice may result in a double-charge of powder. With rifle cartridges, this usually results in a massive powder over-flow, alerting the loader to the problem. With pistol cases or small rifle charges in large cases, such an over-flow isn’t guaranteed. The manually advanced progressive keeps all operations under the loader’s control at all times. This seems intuitively easier for the beginning loader to understand and to operate with confidence. However, this same characteristic can be problematic if the loader isn’t paying 100% attention to what they are doing. Some handloaders apparently prefer to load progressively while daydreaming and paying little attention to the operation. Their plan is to feed components in, like feeding potato chips to a monkey, while good ammo drops out at the other end. Unfortunately, such an approach may well result in something other than “good” ammo dropping out the end – just as happens with the monkey! Forgetting to cycle the shellplate will also cause problems. As with all handloading, distractions MUST be kept to a minimum for safety purposes. Never watch TV, talk with friends, or have other distractions (such as a rambunctious pet or child) in the room when loading. Avoiding distractions will do much to ensure consistent, high-quality ammunition, free of defects.

    For example, when a case doesn’t line up correctly with the case mouth expander or powder drop tube, a difference in “feel” often alerts the loader to correct the problem, avoiding a ruined case. If one is interrupted or becomes distracted, be certain to examine all cases in the shellplate before resuming loading.

    Other advantages of the typical manually-advanced progressives are that they are usually simpler in design, and have fewer moving parts to get out of adjustment. This appeals to the mechanically dis-inclined! Caliber conversion kits are usually cheaper and take less time to install. This especially benefits the enthusiast who reloads for a wide variety of calibers.

    However, many popular manually-advanced progressives have fewer die stations than the higher-end auto-advancing machines. One item that is very useful when actually dispensing powder on a progressive press is a powder-level sensor. This warns if powder levels are too high or too low.
    This condition often results from powder “bridging” in the powder measure. That is, one charge doesn’t fully empty into its’ cartridge case, leaving some extra powder hanging up in the measure to join the normal charge on the next case. With some extruded powders, this can be quite obvious without a sensor. However, the sensor can detect small variations that would not be obvious to even an experienced, attentive operator. Looking at the machine’s potential for a powder sensor, in addition to one’s other customary dies, is a wise idea.

    Similarly, pistol shooters are best served to seat bullets and crimp cartridges in separate operations. This should be taken into account when selecting a progressive press. Whenever loading fully-progressively, choosing powders that dispense very easily, such as ball/spherical or very fine-grain extruded powders, can help keep charges quite uniform.

    The next type of press advances the shellplate automatically each time the handle is cycled. We will discuss this type press and its particular advantages and drawbacks next week.


    Beginning Handloading, Part 5:
    Progressive Presses: Self-advancing Shellplate type


    Happy USAMU “Handloading Hump-Day!” Last week, we addressed manually-operated progressive presses for the beginning handloader. This type press requires one to manually advance the shellplate after each handle stroke. An advantage for beginners is that nothing happens at any station until the loader wants it to. This helps avoid problems from clearing malfunctions without noticing the shellplate has advanced itself.

    [NOTE: Several very useful safety and technical tips re: progressive presses were offered in last week’s column. Any here who missed it are strongly encouraged to read it, as several are not intuitive to people who aren’t well-familiar with progressive presses.]

    The next, more luxurious type progressive advances the shellplate automatically whenever the handle is cycled. Typically, each stroke automatically sizes & primes a case, operates the powder measure (if used) and seats a bullet. Some also have case feeders that automatically put a new case in the shellplate with every cycle. Others require the loader to insert a case each cycle. With both types, the loader usually puts a bullet on each sized/primed/charged case.

    [CAVEAT: While our Handloading Shop has several progressive presses, ALL of our powder charges are thrown/weighed by hand. We do not use powder measures on our presses. Our progressives are used for brass preparation, priming, seating, etc., but not for fully-progressive loading.]

    The manually-advanced press can be a boon to beginners, but as one gains experience it can be a mixed blessing, depending on one’s style. If one pays close attention to every operation and loads without distractions, the manual press is very reliable and allows full scrutiny of each round as it’s loaded. However, if one easily drifts into daydreaming, or isn’t focused on paying careful attention at all times, the manual progressive can be a bit of a liability. The opportunity for forgetting a powder charge, leading to a squib load, is ever-present. The automatically-advancing progressive helps prevent this by ensuring a powder charge will be dropped each time the handle is operated. Experienced handloaders often appreciate this feature due to the savings of time and effort.

    Individual preferences between the two press styles are influenced by several factors. These include one’s comfort with more vs. less complicated mechanisms, how often one changes calibers (case feeders often must be converted, in addition to dies and shellplates), how many rounds one loads annually, relative ease of changing primer mechanisms from small to large, etc. Automatic progressives tend to be significantly more expensive than manual progressives from the same maker.

    One USAMU Handloader, who likes simple, bullet-proof machines and maximum efficiency when converting presses, owns 2 manually-advanced progressives. One is set up for large primers, and the other for small primers. He can change calibers in the twinkling of an eye. As he loads for many different calibers, this fits his style.

    Another Handloader here is just the opposite. He loads for a few calibers, but in larger quantities. He much prefers his self-advancing press with case-feeder for its speed. He makes large “lots” of ammo in a given caliber before switching, to improve overall efficiency. His caliber conversion kits are significantly more expensive than those for the manually-advanced progressive, but he uses fewer of them.

    Whichever type one chooses, it is VERY important to buy quality gear from a manufacturer with a long, well-established track record for quality, durability and good customer support. Avoid jumping on the “latest, greatest” model until it has a proven track record. For example, this writer knows a loader who got a brand-new, expensive, self-advancing model press some years back, shortly after its introduction. As is too often the case, the manufacturer released it before all the “bugs” were worked out. It would not fully seat primers to the correct depth. No amount of adjustment, extra force, or fiddling would do better than to seat primers flush with the case head. Any inattention could result in a slightly “high” primer, protruding above the case head. It created a risk for slam-fires, particularly in semi-autos without spring-retracted firing pins. In desperation, he had a machinist buddy study the problem and machine a new part to correct it. No dice. Its engineering didn’t permit full primer seating, even with extended parts. He now wishes he’d heeded his shooting buddies’ advice to stick with the “tried and true,” reliable performer they all used.

    Whichever press one selects, see if the maker has a kit or list of commonly-replaced parts. Having needed springs, pins, etc. on hand in the rare event that one breaks or “goes missing” can save the day when one is busy loading for a match!

    Next week, we’ll discuss peculiarities of progressive loading for rifle cartridges, with remedies for problems such as excessive cartridge-case headspace variation when sizing, ensuring best powder charge consistency, etc.


    Beginning Handloading, Part 6:
    Progressive Presses: Uniformity of Headspace, Powder Charges & Priming


    Welcome back to the USAMU’s weekly “Handloading Hump-Day!” Last week, we discussed the various types of progressive reloading presses, and covered their advantages and drawbacks for new vs. experienced users. This week, we’ll address some unusual quirks that can occur when loading progressively, particularly for rifle cartridges, plus solutions.

    [CAVEAT: While our Handloading Shop has several progressive presses, ALL of our powder charges are thrown/weighed by hand. We do not use powder measures on our presses. Our progressives are used for brass preparation, priming, seating, etc., but not for fully-progressive loading.]

    For those who like to keep their sized cartridge-case headspace very exact, one aspect of progressive rifle loading is rarely, if ever, mentioned. Setting the full-length (FL) sizing die carefully to the desired headspace length for your chamber is a bit more complex than on single-stage presses.
    Most folks set up and adjust the FL die individually, independent of the other dies on the toolhead. Once they have the headspace where they want it, they then move on to the other dies and consider the headspace setting resolved. Actually, our Shop has measured noticeable headspace differences in cartridge cases sized singly on progressives, vs. those sized when all the dies are working together (i.e., loading fully-progressively). Thus, at the beginning of each loading session, if very-uniform, tight headspace control is an issue to you, check the headspace of the first few cases processed.
    Often, the first 2-3 cases processed, before all stations are working on cartridge cases, will have different headspace than those prepared in the “usual” configuration (shellplate full, all stations active.) Sometimes the difference is minimal, or it can be several thousandths -- perhaps out of the meticulous loader’s “tolerance range.” Such cases, if safe, can be used for sighters, chronographing, practice, etc. Thus, one should minimize running the press without all stations active if the goal is maximum uniformity.

    In like fashion, the powder measure can dispense somewhat different charges when first set up vs. when the machine is fully operational. This occurs when using only the measure station while adjusting the charge, and can be most significant when loading match grade handgun ammunition.
    If one uses the same pistol case several times while adjusting the measure, the case is typically expanded on the first attempt only. Depending on one’ dies, much pressure may be required to remove the expander from the just-expanded case. The press vibrates/jolts differently when loading progressively, and the charge changes.This is especially prevalent when working with virgin brass, as it hasn’t been expanded at the web by firing. With previously-fired pistol brass, the pressure needed to free the case is often much less, affecting the movement of the press & measure during operation.
    This writer finds that, when loading his personal handgun ammunition progressively, setting the measure’s powder charge with a single case gets the powder charge close to the target weight. However, he considers it correct only after the setting has been verified several times while cases are being processed in all stations. Naturally, the amount of variation can differ significantly depending on the type powder used. It is wise to check several powder charges – this verifies that the average charge weight is the one desired. It also gives a picture of how much the powder charges vary, given your particular machine, powder measure, dies, cases and the powder chosen.

    SAFETY TIP: In an earlier column, this writer suggested that new handloaders should learn on single-stage presses until they have a firm, intuitive grasp of each operation. From there, they may begin progressive loading much better prepared to safely prevent and/or diagnose issues as they arise. Being acutely aware of what is happening at each station each time the handle is operated is an important skill. It comes much faster to experienced handloaders.

    An example of this phenomenon may seem obscure, but it isn’t, necessarily – it just isn’t mentioned in print, as far as this writer knows. When progressively loading for .380 ACP, he noticed that cycling the press ram without a case in the expander/powder dump station bumped the shellplate into the expander, raising it slightly. This, of course, partially activates the powder measure on his particular machine.

    Doing this once = a small increase in the next powder charge. Doing it several times in a row, such as when adjusting dies or correcting malfunctions, can make the next charge up to several tenths of a grain heavier than usual.*In a .380 case, that is significant due to the very limited case volume.

    Depending on how heavily one loads, say, the 9x19mm (Parabellum) cartridge, this could also be an issue if the expander/measure die tip can touch the empty shellplate. Another variable is the type of pistol one is using. For example, a Colt 1903/1908 Hammerless Pocket Auto (Model M) in .32 ACP or .380 will happily gobble up ammunition that can badly bulge cases in the new breed of tiny plastic autos. Cases that emerge in excellent condition from the Colts can look like pregnant guppies after firing in certain other pistols. They don’t support the case/lock up the same as the Colts. The bulges witnessed appeared downright scary – very close to bursting the case. The loader actually discarded these cases after firing, due to safety concerns about the effects of such a bulge.While this example may or may not relate to your current handloading, it is good to be aware of such things so one can detect them if they occur in future.

    Priming of rifle cases is another issue on progressive presses. This column has discussed the lengths the USAMU Handloading Shop goes to, to ensure very uniform, safe seating of rifle primers when prepping brass progressively. Primer depth is set to the desired range and checked with a gauge every time a machine is set up to prime. Depths normally vary about 0.001” to 0.003” from case to case. Thus, it’s good to check several to ensure all cases will meet your criteria. Machines that have a positive priming ram stop, which limits depth to the same degree for each case, can and will need adjustment when changing to brass or primers from different makers. Adjustments may even be needed when switching individual production lots from the same maker. Machines without a priming ram stop depend on the operator to fully seat the primer to the bottom of the primer pocket.

    A lesser-known phenomenon when priming progressively – especially with rifle brass – is that primer depth can be significantly different when the shellplate is empty vs. when all stations are processing cases. Thus, settings derived when measuring primer seating depth with only 1 case in the machine should be verified after several cases have been primed with a full shellplate.

    Many, if not most, progressive handloaders would likely consider the differences discussed here to be trivial and insignificant for their loading and accuracy needs. And, they may very well be right! However, the USAMU is addressing an audience interested in extreme rifle accuracy, who want every cartridge as uniform and perfect as they can make it. Thus, we discuss these relatively little-known phenomena in hopes it is educational.

    Certainly, one should never, EVER load ammunition to such high pressures that a 0.2 or 0.3 gr. over-charge can lead to disaster. That is far too fine a line to walk, as infinite variables in components, firearms and weather conditions can affect pressure at any time. Never exceed published, maximum safe data from a reliable, recent handloading manual. Leaving an adequate margin for safety is not only good practice, it is also common sense!

    Next week, we’ll discuss some ways to help ensure that one dispenses the most uniform powder charges possible when loading rifle ammunition progressively. Please join us again!

    Until then, be safe, hold hard, and good shooting!


    Beginning Handloading, Part 7: 29 July, 2015
    Tips to Reduce Metered Powder Charge Variation


    Welcome once again to the USAMU’s weekly “Handloading Hump-Day!” Last week, we gave tips on correcting some progressive presses’ unusual quirks re: uniformity of sized case headspace, primer seating depth and powder charge settings. This week, we’ll delve deeper into methods of minimizing powder charge-to-charge variation.

    [CAVEAT: While our Handloading Shop has many progressive presses, ALL of our powder charges are thrown and weighed by hand. We do not use powder measures on our presses. Our progressives are used for brass preparation, priming, seating, etc., but not for fully-progressive loading.]

    As experienced handloaders know, several variables affect the uniformity of metered powder charges (i.e., those thrown directly from a powder measure.) A small variation is tolerable for all but the most demanding tasks. However, rifle competitors -- in particular, those competing at 600 yards and beyond – will be happiest when charges are as uniform as possible.

    Common factors affecting powder charge uniformity from a measure include, but are not limited to:*
    1. The type powder used – ball/spherical, extruded (including long-grain vs. short-grain versions), and flake versions.
    2. The type of measure used – quality of machining, presence/absence of reservoir baffles, cleanliness (and thus smoothness of operation) and sturdiness of mounting, among others.
    3. The operator: smoothness and above all, UNIFORMITY of operating the powder measure.

    In addition, some progressive presses may induce additional variables not encountered by the single-stage handloader. Of course, when one’s load parameters permit, using a powder that meters evenly can greatly improve charge uniformity. For example, when metering a fine-grain spherical powder for a loading tray of 50 rounds-- by actual count -- this writer only encountered 2 that were 0.1 gr. over or under the desired charge.

    (All 50 charges were check-weighed before funneling them into cases.) Not all ball/spherical powders are this uniform, but as a species, they often contrast nicely to extruded powders. However, many extruded powders offer outstanding performance, particularly at long range.

    A particular long-grain extruded powder meters only about 25 out of 50 charges “correct” to 0.1 gr. from the author’s measure, while a different short-grain extruded powder from the same measure will yield about 35/50 correct. Of course, an operator who has not yet developed a consistent technique may increase variation. Flake powders tend to be fast-burning and most often used in pistol, cast bullet or reduced loads. Thus, they are very frequently metered, not weighed.

    In the author’s experience, many flake powders are difficult to meter precisely, even from top-quality measures. Hence, he once weighed 2,000 .45 ACP match powder charges to 0.1 gr. for use by a Champion-level USAMU Pistol Team member at 50 yards. The shooter reportedly remarked, “It feels like I’m cheating! I haven’t shot a “9” YET!” [I.e., in several hundred rounds of training.] Note that this was an extreme case, for an especially-gifted shooter’s use in 50-yard National-level competition/practice only. Most pistol shooters are well-served by properly-metered charges. Naturally, the labor required to weigh and correct this many charges is tedious and extensive! Whenever a ball/spherical pistol powder can give results equal to, or better than a flake powder, their use can significantly reduce charge variation.

    Next week, we’ll continue this discussion, with particular emphasis on improving uniformity of powder metering when loading progressively.
    Join us! We hope this information will be helpful!



    Beginning Handloading, Part 8:Reducing Powder Charge Variation (Cont'd):

    Welcome back to the USAMU’s weekly “Handloading Hump-Day!” Last week, we discussed factors affecting uniformity of metered powder charges. This week, we’ll continue by addressing specifics of optimum powder metering when loading progressively.

    Powder measures have come a long way in recent decades. Chances are, if one is using a well-made, well-proven design from a respected maker, the measure will be perfectly adequate. Avoid bargains on very old powder measures at estate sales, etc., as some once-popular measures are actually quite inferior to the quality products of today.

    Watch for buildup of powder residue that can cause binding in operation. When this occurs, the measure should be disassembled and cleaned to restore smooth operation. Installing a powder baffle (from your measure’s manufacturer) can help keep powder column pressure uniform.

    Operator-induced powder charge variation generally stems from not having a smooth, standard technique for each measure cycle. Bumping the handle (or not) at the top or bottom of the measure stroke, speed of metering, and dwell time at the top of the stroke (when powder is flowing into the chamber) are all factors that can affect uniformity.

    Checking charge weights on a scale is very useful in assessing one’s performance and charge uniformity. Small powder charge variations are unlikely to make a significant difference in all but the most demanding applications. However, it is not unheard-of to see a 0.7 gr. range of charge weights (or even more), especially when using some extruded powders.

    Progressive presses add another layer to the variables above. Sometimes, the inherent uniformity of press operation can actually improve a new loader’s powder charges! The measures usually supplied, however, are not typically designed for extreme rifle-accuracy use. Polishing the internal and moving parts to reduce burrs and promote smooth powder flow and operation may help.

    Some individual specimens from the same maker may well require more or less tuning than others, depending on the production run. Naturally, progressive press measures differ in design by maker, with some better than others. Moreover, throughout the years, some makers have refined their basic designs to improve operation, resulting in differences between “generations” of their measures.

    To begin, observe the measure in operation and pay particular attention to smoothness of operation. Uneven “jolting” may occur, for example, if the measure bar “sticks” occasionally before returning. Sometimes adding an additional return spring can improve operation. Judicious use of graphite or other dry lube in friction areas may also help.

    Finally, ensuring that the measure is set up properly for the particular cartridge in use is important. Inattention to this can especially cause problems if the measure is not fully cycled. If not carefully adjusted, measures may cycle only partially when loading for a short cartridge, vs. being fully cycled when moved to a toolhead used for a long (tall) cartridge. This should be checked as per the press instructions.

    A different approach altogether is to use a “powder-through” die. This allows mounting a top-quality, manual measure as is found in single-stage loading. If the factory measure is unsatisfactory, one might consider this method. In use, one holds the press handle down, keeping the toolhead raised, and cycles the measure separately by hand. This should give results very similar to those obtained during single-stage loading.

    Some makers offer kits to cycle the high-quality manual measure automatically when the ram is raised. The author has not used this method and cannot comment from experience on its accuracy. Readers with experience using this type setup are invited to share their results here.

    In summary, powder measures, whether used on progressive presses or separately, can be very individual in their behavior. Checking powder charges frequently during operation helps one learn what to expect from one’s measure, and whether tweaks might help. Some measures give near-flawless performance only when the reservoir is half-filled or less. Others from the same maker work very consistently, even when full. Learning ones' measures’ characteristics can make loading more efficient and precise.

    In fact, one might almost be tempted to say, “This is my powder measure. There are many like it, but this one is mine… I will learn its’ habits, its’ preferences, and its’ quirks. Without me, my measure is useless…”

    Good shooting, and be safe out there! Please join us next week for more accuracy-oriented handloading tips!



    Beginning Handloading, Part 9: Cartridge Concentricity


    “Handloading Hump-Day” strikes again! This week, we’ll address some measurements used in precision handloading, and the benefits of periodic QC checks. One handloading motto that addresses this principle is, “I don’t know what I “THINK,” I KNOW what I MEASURE.”

    Many accuracy-oriented handloaders work hard to minimize seated-bullet runout (a.k.a. Total Indicated Runout, {“TIR”} or concentricity). The straighter the cartridge, the better chance the bullet has of entering the rifling well-centered. When 50,000 PSI slams the bullet into the rifling, it deforms to fit. When it does, if its’ center of gravity is thrown “off” due to bullet distortion, an error is introduced, affecting accuracy.

    As measuring tools have become more precise, advanced and available, handloaders have learned to detect and eliminate even small deviations in TIR. However, with the assumed precision implied by modern dial indicators, one must avoid a certain temptation. I.e., there may be lots of space between individual 0.001” increments on one’s dial, but if it’s a 0.001” calibrated tool, that’s the finest measurement it can reliably produce. It may be tempting to assign a value of 0.0018”, say, or 0.0013” due to the needle’s position, but reality is that if it measures to 0.001”, that IS its maximum level of accuracy.

    Another maxim is useful here: just because one CAN measure something, doesn’t necessarily mean that it affects accuracy in a meaningful way. TIR errors might be readily detectable on target using a tight-neck chambered 6PPC steered by a master at 300 yards in flat-calm conditions. However, the same concentricity error may be much harder to reliably detect on target with even a well-built Highpower match bolt gun, and virtually impossible to see when shooting a Service Rifle.

    Many factors combine to affect accuracy and some, such as bedding, bullet quality or poor load development, may be much more powerful than the effect of TIR in any given instance. Thus, while it is certainly good to minimize TIR, this writer suggests taking a “systems-oriented” approach through careful selection and adjustment of reloading dies, brass, etc. Once done, if one reloads consistently, TIR need not occupy more time than a periodic check to ensure the system is still working, or that a new lot of brass hasn’t induced runout, etc.

    Active Highpower shooters fire thousands of rounds in a single season; thus, this is infinitely less labor-intensive than sorting all cartridges individually for runout. Time and energy are resources for the competitive handloader, just as powder, primers and bullets are – and they are not infinite. To produce the best result – i.e., the highest score – one must allocate them consciously and wisely.

    Measuring TIR across the handloading process can, however, be very educational, especially for beginning rifle handloaders. One learns many things. One might be that brass from Maker A gives three times the runout of ammo loaded using brass from Maker B. Another is that ammo loaded in new brass with excellent dies is very likely to have more runout than ammo loaded in the same brass after it’s been fired in a good chamber.
    Excess neck tension can lead to dramatic increases in TIR. This can occur even with dies that would seemingly render high runout impossible, such as Wilson-type straight-line seater dies. As one sees valid, numerical indicators of their precision, one gains confidence in the consistently high quality of their ammunition.

    One can even verify, as this writer has, that a carefully-adjusted set of good, standard hunting dies can produce less runout than an expensive “Match” set, depending on the exact dies used. Or, one can gauge the exact reduction in TIR due to use of individual match-grade dies (i.e., just the seater or just the size die) vs. their standard counterparts.

    Learning about TIR and how to minimize it not only helps one produce consistently high-quality ammunition. It can also verify the value of one’s investment in more expensive dies, or detect processes gone awry.

    This discussion is not intended to prompt beginning handloaders to spend all their free time minimizing runout. Rather, it is intended to put the importance of TIR into perspective, given one’s discipline and rifle, and to help newer shooters avoid wasting time better spent elsewhere.
    Highly-concentric ammunition is always good, but it is only one of many areas of endeavor. One must focus on the areas that will give the most improvement per time/energy invested. Very often, those are practice and dry-fire!

    Until next week, stay safe and enjoy the camaraderie of the shooting sports. It can be just as rewarding as the satisfaction earned by improving one’s scores!



    Beginning Handloading, Part 10: Minimizing Runout with Standard Dies


    Welcome back to the USAMU’s “Handloading Hump-Day!” Last week, we addressed factors affecting loaded-cartridge concentricity (AKA “TIR”, or Total Indicator Runout). That refers to the bulle,ts’ straightness in the case, which affects deviation as the bullet enters the barrel and is fired. This is best optimized by systematically reducing runout-inducing factors in one’s loading process and die adjustment. Checking and sorting the thousands of cartridges an active Highpower shooter uses per season is excessively time-consuming.

    Here, we’ll discuss minimizing TIR using standard, good-quality “hunting” dies, rather than highly-expensive match dies. We’ll do this with a single-stage press, rather than a progressive, as most newer handloaders will have a single-stage. First, a QUALITY-made tool for measuring TIR is essential for obtaining consistent, accurate results.

    Generally, measuring equipment is NOT a good area in which to “skimp” or economize, as one uses these tools throughout one’s handloading career. They form the basis for consistent reproduction of accurate ammunition lots. For the budget-conscious, the fact that high-quality tools hold their value very well helps reduce the sting. Moreover, they’re generally very easy to sell when no longer needed. Thus, whatever little loss one might take on depreciation should be considered as “rent” on the tools for the years/decades they are used. This author actually sold a used micrometer for MORE than he originally paid 20 years ago, although inflation probably accounts for the “profit.” Still, quality tools retain value, while junk tools do not.
    This post will cite experiments the writer conducted and published over 20 years ago, but the techniques and measurements still remain valid. With truly advanced-design, high-quality and precisely-machined match dies, one gets more precision and less variation/TIR for their money. However, for those who are not sure they want to remain with the sport, or who wish to economize, it’s entirely possible to load very concentric ammunition using standard dies of the RCBS/Redding, etc. type.

    A lesser-known approach to this is to use a rubber O-ring under the Full Length (FL) sizing die lock ring. These are easily found at hardware stores. Place the O-ring on the die body between the lock ring and the top of the press, leaving the lock ring loose. Then, run a lubed case into the die, and begin adjusting the die to give the desired sizing/case headspace. (I.e., set the shoulder back to the desired dimension for one’s chamber.)
    Many tools exist for case headspace measurement. Among them, one which is quick and easy to use is the RCBS Precision Mic. It measures case headspace on a scale calibrated to one’s specific cartridge, such as .223 or .308, etc. Once this sizing adjustment is correct, run the sized case BACK into the die, to keep it centered and under tension. Then screw the lock ring down onto the O-ring to affix the die in place, and set the lock screw.
    IMPORTANT: Be sure to leave enough clearance between the top of the press and the lock-ring to let the die “float” slightly if you exert pressure on it with your hand. This allows the die to “self-center” in use. Once the lock-ring screw is tightened, the above steps need not be repeated. Whenever re-setting the size die, as when changing calibers, or if changing from military (hard) to commercial (softer) brass, just screw the die into the press until the O-ring contacts top of the press. Then, test-size cases and measure them with your headspace gauge, adjusting the die slightly up or down until the desired measurement is repeatedly obtained. This method can noticeably reduce TIR.

    NOTE: One maker of inexpensive loading gear incorporates an O-ring into their lock-rings, but this should not be confused with the method above. Their O-ring supplies friction to maintain the lock-ring in position on the die, rather than using a positive locking screw, and does not facilitate the method used here.

    To further decrease seated-bullet runout, avoid excessively working case necks during sizing. Expander balls are routinely cited as a culprit in inducing neck distortion, which causes crooked bullet seating. A common solution is to remove the expander ball. However, standard dies are must work with cases having just about any neck-thickness on the planet, Thus, they typically size the case neck down excessively, and then use the expander ball to bring them back up for the desired neck tension.

    A good range of case-neck expansion (from sized/empty to expanded after seating the bullet) is 0.003”-0.004”. For example, if the sized neck measures 0.300” before seating, it will measure 0.303”-0.304” after bullet seating. This is usually considered enough neck tension for normal use with excellent accuracy, including cycling in an AR-15, AR-10, or M1A WITHOUT CRIMPING unless some problematic condition (e.g., feed ramp issue) is present. Excessive neck tension can reduce accuracy, in and of itself.

    If one’s FL size die reduces case necks excessively for use without the expander ball, there are several remedies. One may take it to a machinist or send it to the mfg. to be honed out to the desired dimension. One may also modify the die to accept interchangeable neck-sizing bushings (available in 0.001” diameter increments.) Avoiding expander balls also eliminates the need to lube inside the case necks (although brushing them clean is still recommended.)

    Results of an experiment comparing TIR in 50 rds of .308 match ammo loaded using carefully-adjusted standard dies, vs. 50 using “Match” dies from the same maker that cost 3 times as much, both with O-rings, are given below:
    Standard dies, TIR:*
    0.000”- 0.001” = 52%;
    0.001”- 0.002” = 40%;
    0.002”-0.003”: 8%. None greater than 0.003”.
    Lesser-quality “Match” dies, TIR:*
    0.000”- 0.001” = 46%;
    0.001” – 0.002” = 30%;
    0.002” – 0.003” = 20%;
    0.003” – 0.004” = 4%.

    NOTE: Especially when using cases previously fired in a concentric chamber, as was done above, more advanced, industry-leader match dies can produce ammo with virtually NO TIR when care is taken throughout the loading process.

    NOTE: ALL MATCH DIES ARE NOT CREATED EQUAL. Ask experienced, well-accomplished handloader/Highpower competitors which brands they have had excellent results from. Then, pay attention to the manner/degree with which they evaluate their results, as not all are equally methodical about such things.

    COMING UP NEXT WEEK: Minimizing TIR by carefully adjusting standard seating dies.


    Beginning Handloading, Part 11:
    Minimizing Runout with Standard Dies (Cont’d.)
    Aug. 26, 2015



    Once again, it’s time for USAMU’s “Handloading Hump-Day!” Last week, we addressed achieving very good loaded-cartridge concentricity (AKA “TIR”, or Total Indicator Runout) using standard, “hunting grade” reloading dies. We explained how to set up the FL size die to float slightly when correctly adjusted for desired case headspace. We also cited a study in which this method loaded ammunition straighter than a set of “2nd-Tier” match dies from the same maker.

    Now, we’ll set up a standard seating die to minimize TIR – the other half of the 2-die equation. As before, we’ll use a single-stage press since most new handloaders will have one. A high-quality runout gauge is essential for obtaining consistent, accurate results.

    Having sized, primed and charged our brass, the next step is bullet seating. Many approaches are possible; one that works well follows. When setting up a standard seating die, insert a sized, trimmed case into the shellholder and fully raise the press ram. Next, back the seating stem out and screw the die down until the internal crimping shoulder touches the case mouth. Back the die out ¼ turn from this setting to prevent cartridge crimping. Next, lower the press ram and remove the case. Place a piece of flat steel (or window glass, which is quite flat) on the shellholder and carefully raise the ram. Place tension on the die bottom with the flat steel on the shellholder. This helps center the die in the press threads. Check this by gently moving the die until it is well-centered. Keeping light tension on the die via the press ram, secure the die lock ring.
    If one were using a match style, micrometer-type seating die, the next step would be simple: run a charged case with bullet on top into the die and screw the seating stem down to obtain correct cartridge OAL. However, with standard dies, an additional step can be helpful. When the die has a loosely-threaded seating stem, set the correct seating depth but don’t tighten the stem’s lock nut. Leave a loaded cartridge fully raised into the die to center the seating stem. Then, secure the stem’s lock nut. Next, load sample cartridges and check them to verify good concentricity.

    One can also experiment with variations such as letting the seating stem float slightly in the die to self-center, while keeping correct OAL. The runout gauge will show any effects of changes upon concentricity. However, the first method has produced excellent, practical results as evidenced by the experiment cited previously. These results (TIR Study 2) are reproduced below for the reader’s convenience

    First, however, let’s examine runout figures of some factory-loaded match ammunition. This should give readers who are new to TIR gauges some perspective about the TIR ranges one might encounter.

    TIR Study 1: 50 rds Lake City M852 Match 7.62mm (168 gr. Sierra MatchKings)
    0.000” – 0.001” = 2%
    0.001” – 0.002” = 30%
    0.002” – 0.003” = 16%
    0.003” – 0.004” = 22%
    0.004” – 0.005” = 14%
    0.005” – 0.006” = 14%
    0.006” – 0.007” = 0%
    0.007” – 0.008” = 2%


    TIR Study 2: 50 rds of .308 match ammo loaded using carefully-adjusted standard dies, vs. 50 using expensive “Match” dies from the same maker. Note: both samples were loaded using the O-ring method explained last week.
    Standard dies, TIR:*
    0.000” -- 0.001” = 52%;
    0.001”-- 0.002” = 40%;
    0.002”-- 0.003” = 8%. None greater than 0.003”.
    Lesser-quality “Match” dies, TIR:*
    0.000”-- 0.001” = 46%;
    0.001” -- 0.002” = 30%;
    0.002” -- 0.003” = 20%;
    0.003” -- 0.004” = 4%.

    These tips are intended to help shooters obtain the best results from inexpensive, standard loading dies. Especially when using cases previously fired in a concentric chamber, as was done above, top-quality match dies and brass can easily yield ammo with virtually *no* runout, given careful handloading.

    Beginning Handloading, Part 12:
    Six Key Tenets of Service Rifle Loading


    Welcome back to USAMU’s “Handloading Hump-Day!” Last week, we concluded a 2-part series on setting up standard, “hunting” style dies for minimal runout, with concentricity gauge results. Today, we offer some “cardinal rules” to help new gas-gun handloaders with safety and efficiency. These address both Match Rifle and Service Rifle versions of the AR15, M1 Garand, M1A, and M110. However, they can also improve safe reloading for many other auto-loaders such as M1 Carbines, FALs, SIGs, etc. The author distilled these principles many years ago to help focus on the essential aspects of these rifles.


    RULE 1: SERVICE RIFLES ARE NOT BENCHREST RIFLES.
    Gas-guns require a relatively loose fit between ammunition and chamber (vs. bolt actions) for safe, smooth operation. Many techniques, such as neck sizing and keeping cartridge headspace quite tight, are popular in the extreme bolt gun accuracy realm. However, they are of little value with Service Rifles, and some could even be hazardous. Before adopting a specialized technique, seriously consider whether it is appropriate and beneficial in a gas-gun.

    RULE 2: NEVER COMPROMISE SAFETY TO OBTAIN ACCURACY.
    Example: if choosing a brand of great, but ultra-sensitive match primers offers possibly better accuracy at the risk of slam-fires in your design of rifle, don’t do it! You are issued exactly 2 eyes and 10 fingers (best-case scenario). Risking them trying to squeeze 0.25 MOA better accuracy out of an M1A, etc. simply isn’t worth it.

    RULE 3: TAILOR THE PRECISION YOU ADOPT TO YOUR INDIVIDUAL SKILL AND YOUR RIFLE'S POTENTIAL.
    This has been addressed here before, but bears repeating for new-comers. If you are struggling to break out of the Marksman class, or using a CMP M1 “as-issued,” then laboriously turning the necks of your 600-yard brass is a waste of time. Your scores will improve much faster by practicing or dry-firing.On the other hand, if the reigning champions anxiously check your scores each time you fire an event, a little neck-turning might not be so far-fetched. Accuracy handloading involves a wide variety of techniques, ranging from basic to rather precise. Carefully select those which offer a good return on investment for your time and labor. In doubt? Do a classic pilot study. Prepare ammo for at least 3-4 ten-shot groups with your new technique, vs. the same with your standard ammo. Then, pick a calm day and test the ammo as carefully as possible at its full distance (e.g., 200, 300 or 600 yards) to verify a significant improvement. A little testing can save much labor!

    RULE 4: BE YOUR OWN EFFICIENCY EXPERT.
    Serious Service Rifle shooters generally think of ammunition in terms of thousands of rounds, not “boxes,” or even “hundreds.” Analyze, and **write down** each step in your reloading process. Count the number of times each case is handled. Then, see if any operations can be dropped or changed without reducing safety or accuracy. Eliminating just 2 operations saves 2000 “steps” per 1000 rounds loaded. Conversely, carefully consider any measurable benefits before adding a step to your routine.

    RULE 5: IN SEARCHING FOR GREATER ACCURACY WITH EFFICIENCY, LOOK FOR SYSTEM CHANGES.
    For example, instead of marking your 300-yard rounds individually to differentiate them from your 200-yard ammo, would a simple change in primers work? If accuracy is maintained, using brass-colored primers for 200 and silver for 300 provides an indelible indicator and eliminates a step! Similarly, rather than spending hours selecting GI surplus brass for weight and neck uniformity, consider splurging on some known, high-quality imported match brass for your 600 yard loads. Results should be excellent, time is saved, and given limited shooting at 600 yards, brass life should be long.

    RULE 6: CHECK ALL PRIMERS BEFORE PACKAGING AMMO.
    This seems simple and even intuitive. However, many slam-fires (which were much more common when M1’s and M1A’s were the standard) are due, at least in part, to “high” primers. Primers should be seated below flush with the case head. The USAMU has addressed this at length in a previous column, but each round should be checked for properly-seated primers before they are packaged for use.

    Thanks for joining us, and we hope these tips will be helpful to new Service Rifle handloaders! Be sure to visit us again next week for more tips and techniques!


    Beginning Handloading, Part 13:Extrapolating Beyond Your Data, or…“I Don’t Know, What I Don’t Know!"

    Welcome back to the USAMU’s weekly “Handloading Hump-Day!” Last week, we addressed several key facets of Service Rifle reloading. Today, we continue our Handloading Safety theme, focusing on not inadvertently exceeding the boundaries of known, safe data.

    Bullet manufacturer’s loading manuals often display 3, 4 or more similar-weight bullets grouped together with one set of load recipes. The manufacturer has tested these bullets and developed safe data for that group. However, seeing data in this format can tempt loaders -- especially new ones -- to think that ALL bullets of a given weight and caliber can interchangeably use the same load data. Actually, not so much. The researchers ensure their data is safe with the bullet yielding the highest pressure. Thus, all others in that group should produce equal or less pressure, and they are safe using this data. However, bullet designs include many variables such as different bearing surface lengths, hardness, and even slight variations in diameter. These can occasionally range up to 0.001” by design. Thus, choosing untested bullets of the same weight and caliber, and using them with data not developed for them can yield excess pressures.

    This is only one of the countless reasons not to begin at or very near the highest pressure loads during load development. Always begin at the starting load and look for pressure signs as one increases powder charges.

    Bullet bearing surface length (BSL) is often overlooked when considering maximum safe powder charges and pressures. In Photo 1, note the differences in the bullets’ appearance. All three are 7mm, and their maximum weight difference is just five grains. Yet, the traditional round nose, flat base design on the left appears to have much more BSL than the sleeker match bullets. All things being equal, based on appearance, the RN/FB bullet seems likely to reach maximum pressure with significantly less powder than the other two designs.

    Due to time constraints, the writer used an approximate, direct measurement approach to assess the bullets’ different BSL’s. While fairly repeatable, the results were far from ballistics engineer-grade. Still, they are adequate for this example.
    Bullet 1 (L-R), the RN/FB, has a very slight taper and only reaches its’ full diameter (0.284”) very near the cannelure. This taper is often seen on similar bullets; it helps reduce pressures with good accuracy. The calculated BSL of Bullet 1 was ~0.324”.

    The BSL of Bullet 2, in the center, was ~0.430”, and Bullet 3’s was ~ 0.463”. Obviously, bullets can be visually deceiving as to BSL!
    Some might be tempted to use a bullet ogive comparator (or 2) to measure bullets’ true BSL for comparison’s sake. Unfortunately, comparators don’t typically measure maximum bullet diameter and this approach can be deceiving.

    In Photo 2, two 7mm comparators have been installed on a dial caliper in an attempt to measure BSL. Using this approach, the BSL’s differed sharply from the originals. Bullet 1’s new BSL was 0.694” (vs. 0.324”), Bullet 2: 0.601” vs. 0.430” and Bullet 3: 0.602” vs. 0.463”.


    Beginning Handloading, Part 14: Extrapolating Beyond Your Data, Part 2

    Welcome back to the USAMU “Handloading Hump-Day” column! Last week, we discussed the effects of bullet bearing surface length (BSL) and other variables that can affect pressure and velocity when developing handloads. Readers who missed Part 13 (9 Sept. 2015) may wish to go back and review our discussion on measuring bullet bearing surface length (BSL). We discussed an approximate method of measurement, plus avoiding a possible pitfall.

    But, wait!! There’s more! What we measured was the PRE-firing bearing surface length. Remember the long, gradual taper of the RN/FB bullet before it reached full diameter? When the bullet is thrust forward upon ignition, it is pressure-swaged to fit the bore. Given the bullets’ long, tapered portion which is just slightly under 0.284”, some portion of that becomes bearing surface. Thus, the “official” 0.284” BSL that we measured isn’t the only bullet bearing surface engagement effect in play. This less-obvious factor will contribute to the pressure curve rate and total chamber pressure. Now, how much total bearing surface length (during firing) is there? Hmmm… The calipers didn’t show us that…

    So, what is the effect of any bullet’s post-ignition BSL upon chamber pressure? It includes many variables: e.g., jacket thickness and material, core hardness, bore diameter, throat type, rifling form, bullet “jump” to rifling, propellant burn rate, etc.* Now, picture the vast array of bullet designs and constructions, powders with different burn rates, etc…

    The logical answer to accurately predicting these effects on pressure without rather complex computer input and modeling is, “I don’t know.” That’s no problem. I don’t NEED to know. What I DO need is to maintain respect for the pressures and variables involved, and develop handloads carefully, knowledgeably and with due caution. The key take-away point is, “Now I KNOW what I don’t know.”
    Consider (hypothetical) Bob, who loves his classic, pre-war M1903 Mannlicher-Schoenauer 6.5x54mm sporter. He just found a major bargain on its’ preferred 160 gr. RN/FB bullets. The local sporting goods store sold him several hundred rounds of World War II, German-manufactured 6.5x53R Dutch Mannlicher ammo loaded with these bullets. They were extremely cheap because the case necks had cracked in storage.

    That was no problem – all he wanted was the bullets, and they were of the correct design, weight and diameter for his rifle. Heck, he could even pull them just using his fingers – they were pristine! “What could possibly go wrong?”

    Bob wasted no time in seating his new bargain bullets over his long-time favorite, maximum hunting powder charge. He “knew” the load data was good, as he’d carefully developed it in his rifle using high-quality soft-points. He had chronographed his increasing loads while observing for pressure signs until he reached the correct velocity with a safe charge, as per his manual. All was normal; case life and accuracy were excellent.

    Upon firing the new Franken-ammo, however, things changed… quickly and drastically. His beloved hand-built, highly valuable Austrian sporter blew a primer, and the stock was wrecked. Why? Well, war-time being what it was, the Germans conserved copper by using steel jackets for their ammunition, with an extremely thin copper “flash”. Naturally, steel reacts to pressure a bit differently than the copper jackets Bob had used earlier. Had Bob thought about it, he could have checked the jacket material with a magnet…
    And, being military, the steel jackets were thick. They were designed for barrier penetration, rather than expansion. Moreover, the German core material was not virgin, soft lead, but a harder alloy. Bob’s “find” was no bargain. It was a net loss on his beloved, irreplaceable rifle -- but luckily, he did NOT lose any beloved, irreplaceable fingers or eyes. This time.

    Hopefully, this dramatic, if fictional, episode will help ingrain an image into the reader’s memory. Perchance it will even leap to mind like a cautionary Jiminy Cricket, should readers be tempted to experiment a bit too exuberantly. Join us again next week for the conclusion of this handloading safety series, plus another of our thrilling, true-life “Don’t Be That Guy!” episodes!
    Attention to detail is our watchword for today. Shoot well!


    Beginning Handloading, Part 15: Extrapolating Beyond Your Data, Part 3

    Today, the USAMU’s “Handloading Hump-Day” concludes this 3-part series on variables that affect pressure. However, it’s by no means all-inclusive!

    Loading manuals frequently caution readers to re-develop loads whenever changing a major component: bullet, primer, cartridge case or even powder lot to avoid possible pressure problems. Many other variables affect pressure; one is bullet engraving force.
    This is an obvious concern when using cast lead bullet data (i.e., very low engraving force) to load jacketed bullets. They have a much higher engraving force and can develop higher pressures or faster pressure spikes. However, cup-and-core bullet jackets vary greatly in thickness depending upon the design and maker, which can significantly affect pressure.

    The percent of antimony in bullets’ lead cores affects hardness, and thus pressure. Bullets with similar weights but different ogive shapes can put one bullet well off the rifling at a given cartridge length, whereas another at the same length engages the rifling heavily, etc.

    Today, bullets are increasingly being made of solid copper or other non-traditional materials. Depending upon the bullet design, this can significantly increase engraving force.

    An early pioneer in solid copper bullet manufacturing instructed users to seat bullets 0.050” or greater from the rifling, which helped reduce pressure and improved accuracy. Later designs incorporate machined rings in the bearing area that reduce bore contact (BSL). They also allow the copper engaging the rifling to deform into the relief areas, reducing fouling.

    The foregoing is not intended to start readers calculating which bullet designs they might launch just below light-speed while ignoring published load data. Rather, it is intended to help beginning handloaders see a few of the less-obvious variables that can affect pressure. There are many more.

    Avoiding the temptation to make assumptions beyond the known data, act upon them and then place one’s face behind 60,000 (++?) PSI seems wise!

    ***And now, we bring you another true episode of “DON’T BE THAT GUY!”***

    Decades ago, a gun store owner of the writer’s acquaintance reported the following: a friend had asked him to reload some .30-30 ammunition for his trusty Winchester 94. Despite knowing better, he grabbed a popular reloading manual, found the powder and charge giving the highest velocity for his bullet weight, and commenced assembly.

    Later, his friend asked, “What did you put in those things, rocket fuel?? Every time I shoot it, it blows the lever open!” The proprietor wasted no time in retrieving the thermo-nuclear cartridges and replacing them with a more sedate version. Only luck and John Browning’s design talents prevented a spectacular, instant disassembly!

    Handloading is a safe, fascinating and very rewarding pastime when done correctly. Just remember, be safe out there! When researching data for new load development, always use the most recent data available, and check more than one reloading manual. Cross-checking can give valuable insights into differences between individual barrels, barrel length effects, and bullet designs.
    Avoid any temptation toward wildly impetuous ballistic experiments, and enjoy the shooting sports for many happy years to come!


    Beginning Handloading, Part 16: Economy, Handloading and Training Value

    Today’s “Handloading Hump-Day” will shift focus from technique to logistics, to help our readers literally get the most “bang for their bucks!”

    The usual progression of new handloaders is: (1), get some gear; (2), learn to handload and (3), be delighted with their savings vs. buying factory ammo. This generally translates into spending just as much money, but having lots more good ammunition to show for it. That’s not a bad thing; more high-quality practice generally leads to greater skill. Eventually, many new handloaders become more knowledgeable and enthusiastic, and begin refining their gear and technique. Then, handloading becomes a fascinating hobby in its own right!

    Active competitive shooters have goals to meet, and handloading is the means to reach them. Unfortunately the cost of reloading components has, in most cases, literally doubled in recent years. Newcomers are at an economic disadvantage relative to the shooters of only a few years ago. It is difficult to practice the desired amount when costs are high. There are ways to develop skill without shooting as much higher-cost, match-grade ammunition. Many don’t involve live ammo, so we’ll cover the handloading aspects here.

    The better approaches do not include the popular, novices’ idea of buying “cheap” military surplus or “combat/plinking” grade ammunition. That is almost never a bargain given the accuracy we require, the skill we intend to achieve and the cost in barrel life expended vs. accuracy obtained (i.e., training value). Even years ago, when high quality surplus .308 FMJ ammo was plentiful at $3.00/20 cartridges, it was of only limited training value. Now that similar ammunition costs $12.00 - $20.00/20, it is even less useful.

    Happily, the cost of training with one’s AR-15 Service or Match Rifle can be significantly reduced. Using the popular .223/5.56mm caliber for our example, let’s see how to save money and train more, with excellent results. A quick scan of some well-known, on-line component vendors reveals that the widespread-favorite 77 gr. match bullets now cost ~$28.50/100.
    Thus, full-distance 200/300 yard match handloads using top-quality powder and match primers will cost ~$8.64 per 20-rd box, not counting brass. This compares quite favorably with the “go-to” maker’s 77 gr. match ammo at $23.99/20. Handloaders save ~$767.50 per 1000 rds, and both loads use the same brand of match bullets! (These figures are approximate; shopping around, buying in quantity, etc. can save still more money.)

    Not all training can or will be done at 200, 300 and 600 yards. Many ranges are limited to 100 or 200 yards. Thus, shooting is done on official, reduced-distance versions of the standard 200, 300, and 600 yard targets. Training at 100 or 200 yards very rarely requires the 77 gr. bullets’ special wind-bucking ability.

    We can use the “go-to” maker’s 52 gr. match HPBT bullet at $21.49/100, excellent but less-expensive powder and good, standard primers. This yields superbly accurate 100/200 yard practice ammo at ~$6.46/box, and savings increase by another $109.00 per 1000 rounds. That’s good, but we can still do better!

    Having cut the price of our ammunition significantly while retaining great accuracy, we’ve done well so far. However, we’re nothing if not resourceful, and now is not the time to rest on our laurels. Join us again next week for Part 2 of this article.

    We’ll explain another radical reduction in our handload cost, again with excellent accuracy, plus an equipment approach that can save shooters thousands of dollars over their careers!
    In the meantime, hold center and be safe!



    Beginning Handloading, Part 17: Economy, Handloading & Training Value, Part 2

    Today, “Handloading Hump-Day” resumes our discussion of loading accurate ammunition economically. Readers who missed Part 1 of this article may wish to read our earlier post of 30 Sept. 2015 for very useful information.

    Having covered the basics of making more economical choices and optimizing ammunition for training, we’ll look at even more ways to save money while obtaining excellent results. Now, it gets interesting.
    Remember those bulk 55 or 62 gr. FMJ bullets that are said to be a “bargain?” Well, their accuracy is typically rather ghastly, by NRA Highpower Rifle standards. Moreover, a quick scan reveals a much better, very cost-effective alternative. As a rule, open-tip bullets (i.e., solid base, soft points or hollow points) tend to be much easier to make accurate than FMJ (open base) bullets.

    For AR-15 use, HP bullets are preferred due to the SP’s exposed lead tips being damaged by feed ramps. Some major, online reloading component suppliers market “house brand” 50-55 gr. HP “varmint” bullets (which actually come from a “famous maker.”) One company’s are more economical than the others, at $51.50/500, or $10.30 per 100. This is actually lower than the cheapest 55 gr. FMJ’s found -- and the HPs give excellent accuracy! Recently, a USAMU Handloading Shop staffer used them to easily develop a load averaging 0.6” at 100 yards with 5-shot groups from the bench (not machine rest). This was in a good, but not top-tier AR-15 varmint barrel. Combining these varmint bullets with our other less-expensive components brings cost down to just $4.22 per 20, or $211.00/1000 rounds. This is ~$221.00/1000 cheaper than the full-distance, 77 gr. match handholds.

    Of interest, the lighter 55 gr. bullets reduce barrel wear vs. the 77 gr., and the less-expensive spherical powders meter beautifully. This can greatly reduce time spent reloading vs. the extruded powders used in the premium match handloads. A little math shows that using the inexpensive -- but quite-accurate -- training ammo for just 2,000-3,000 rounds will save enough vs. the 77 gr. match handloads to pay for a top-quality match barrel and installation!

    But, why stop there? While not strictly handloading-related, another cost-control strategy is to avoid discarding high-quality match barrels early. When AR-15 barrels used in competition may be past their accuracy prime for use at 600 or 300 yards, they often retain excellent accuracy at 100/200 yards, especially with the more blunted-ogive 52-55 gr. HP bullets.
    When seated to magazine length, their ogives sit significantly closer to the rifling than those of the more streamlined bullets. Often, these barrels may remain accurate for several thousand more rounds, especially with the lighter (more blunt) bullets.

    In Photo 1, we compare two magazine-length handloads: one with a popular 77 gr. match bullet, and one with the “house brand” 55 gr. economy HP varmint bullet discussed above. Seated to identical length and checking with an ogive comparator, the 55 gr. bullet sits ~0.086” closer to the lands than the 77 gr.

    While this can be significant, other bullet designs can make a dramatic reduction in the “bullet jump to rifling” when feeding from the magazine. This writer has seen group sizes cut in half, or better, from worn match barrels or USGI barrels with a long, NATO throat when using particular 50-55 gr. bullets.

    One, in particular, seems to be the “magic bullet,” as it were. A premium maker’s 55 gr. varmint HP, it has such a gaping opening at the front that it far outclasses the others in reducing bullet jump. In fact, in newer barrels with certain match chambers, it must be seated significantly shorter than normal magazine length in order to avoid jamming it into the rifling! Due to its’ very blunt profile, reliability is best in rifles with M4 feed ramps. If dim memory serves, it may have a factory item number of 1390, or similar.

    Rather than discarding one’s first “shot-out” match barrel, test it with light bullet handloads. If accurate enough, this upper receiver assembly can be used for 100/200 yard training -- including the extended rapid-fire practice sessions which erode barrels relatively quickly.

    The new match barrel is fitted to a new match upper, handloads are developed, and it is reserved primarily for full-distance match use. The new barrel will last longer, as it is not being used nearly as much for training. By the time the new barrel nears replacement, the old, training barrel should be well-used. It is discarded, its’ upper gets a new match barrel, and it becomes the new designated match upper.
    The just-demoted, former “match” upper with the now-aging barrel (i.e, the second one built) should still retain lots of life. It is relegated to training use, and eventually the process repeats. Thus, one saves quite a bit over time in replacement barrel cost.

    Moreover, one can use any given, freshly-rebarreled match upper in competition for much longer before replacement, due to reduced wear from training. This means a longer period using one’s match loads in competition before switching barrels, and less load development.

    At first glance, this may seem expensive due to the need for 2 upper receivers, free-float handguards, bolt carriers, etc. rather than just one. However, in the big picture, remember the old saying that one doesn’t “buy” top-quality, durable gear, one merely pays “rent” while using it.

    That is, should one retire from competitive shooting or change disciplines, quality used gear can often be sold for a good percentage of its original cost. Moreover, some items, like best-quality match receiver sights or optics, may bring most or even all of their original cost when they are eventually sold.

    Bottom line: even with today’s higher component prices, handloaders still save tremendously vs. the price of factory ammunition. They also have full control over the performance of their ammo in their rifles. Even today, there are still bargains to be had, if one knows where and how to shop!

    We hope these articles will help new handloaders learn ways to save money while still maintaining fine accuracy, thus allowing more skill development per dollar available.
    Come see us at Camp Perry!



    Beginning Handloading, Part 18: Economy, Handloading & Training Value, Part 3

    Today, “Handloading Hump-Day” concludes our discussion of loading accurate ammunition economically. Readers who missed Parts 1 and 2 of this series may wish to read our 30 Sept. & 07 Oct. posts for very useful information.

    To review, open-tip bullets (i.e., solid base, soft points or hollow points) tend to be much easier to make accurate than FMJ (open base) bullets. Therefore, we explored the use of lighter, 50-55 gr. varmint or match bullets for accurate, less-expensive practice at 100-200 yards.

    When choosing hunting bullets for AR-15 use, HP bullets are preferred due to the SP’s exposed lead tips being damaged by feed ramps. In last week’s example, we reduced the cost of 1000 match-accurate 55 gr. HP .223’s to $211.00/1000 rds., or $4.22/box of 20.

    We also discussed the benefits of bullets with a more blunt profile for short-range use, as their ogives are nearer to the lands than their more streamlined cousins. This can be especially helpful in improving accuracy in barrels with worn throats or over-sized, long-throated military chambers. Bullet designs vary, and some 50-55 gr. bullets jump significantly farther to reach the rifling when seated to magazine length than others.

    Several years ago, before the recent component shortages and price hikes, handloaders had a wide variety of bullet styles to choose from, at prices about half the current rate. At present, obtaining any particular bullet design/weight can be a matter of timing, as they go into production, are snapped up on the market, and disappear again for several months or longer.

    Thus, being able to take a quick, educated guess at bullets’ relative performance when seated at magazine length, based on their bullet jump, can be helpful. This is especially true when using worn or NATO-chambered barrels.

    To illustrate, this writer measured several available bullets using an ogive comparator when seated to 2.260” OAL. Inclusion or exclusion from this list does not imply endorsement or lack thereof by the U.S. Army Marksmanship Unit. It merely represents a sampling of available bullets for educational purposes. The measurements are from cartridge-base to ogive.
    Bullets with longer measurements jump less to the rifling than those with shorter base-ogive lengths. For example: compare the 50 gr. Speer TNT with the Sierra 55 gr. BTHP. The difference is 0.119”; thus, the Sierra sits *approximately* 0.119” closer to the rifling than the Speer.

    **NOTE: The 80 gr. Sierra MK is included at magazine length to show the relative jump of a long-range, single-load, high-BC bullet. This should help illustrate 1 reason why they are very rarely, if ever, used at magazine length.

    Bullet Wt. Maker/Style B-O Length
    40 gr. Hornady V-MAX 2.837”
    40 gr. Nosler Ball. Tip 2.822”
    50 gr. Hornady V-MAX 2.830”
    50 gr. Speer TNT HP 2.805”
    52 gr. Sierra MatchKing 2.877”
    55 gr. Berger BR HP 2.835”
    55 gr. Hornady V-MAX 2.840”
    55 gr.. Sierra BTHP 2.924”
    60 gr. Sierra HP 2.860”
    62 gr. IMI M855 FMJ 2.807”
    69 gr. Sierra MatchKing 2.820”
    **80 gr.** Sierra MatchKing 2.705”

    If a particular bullet of interest becomes available for which one has no data, networking with friends to get a sample bullet might help. While today’s handloaders face periodic challenges in getting components for economical practice ammo, it can still be done and is still worthwhile. We hope this series will be helpful!
    Good luck, and good shooting!



    Beginning Handloading, Part 19: Cartridge Efficiency: A Primer (pun intended!)

    Welcome back to the USAMU’s weekly “Handloading Hump-Day” column! This week, we’ll give a quick overview of cartridge case efficiency and its benefits.
    Due to time and space limitations, we cannot cover this topic in depth, but will address certain key aspects that newer handloaders may want to consider. Once familiar with these issues, one is better equipped to evaluate calibers under consideration.

    While this is oriented primarily toward NRA Highpower Rifle and Long Range (1000 yard) competition, these factors also apply to medium/big game hunters. Assuming one’s rifle and ammunition are accurate, key considerations include ballistic performance (i.e., resistance to wind effects, plus trajectory), recoil and throat erosion/barrel life.

    Whether choosing a cartridge for competition or hunting, the availability of bullet designs suitable for your caliber, velocity and your range to target is very important. For hunters, a bullets’ terminal performance at typical striking velocities on expected game is essential. Do available bullets expand, penetrate adequately, fragment vs. hold together, etc.?

    For competitive shooters, this issue is moot; rather, pristine accuracy and ballistic performance in the wind are critical. Flat trajectory benefits the hunter who may shoot at long, unknown distances (nowadays, range-finders help). However, this is of much less importance to competitors firing at known distances.

    Recoil is an issue, particularly when one fires long strings during competition, and/or multiple strings in a day. Its effects are cumulative; cartridges with medium/heavy recoil can lead to shooter fatigue, disturbance of the shooting position and lower scores. Some find this more of an issue than others, of course.

    For hunters, who may only fire a few shots a year, recoil that does not induce flinching during sight-in, practice and hunting is a deciding factor. Depending on their game and ranges, etc., they may accept more recoil than the high-volume Highpower or Long Range competitor.

    Likewise, throat erosion/barrel life is important to competitive shooters, who fire thousands of rounds in practice and matches, vs. the medium/big game hunter. A cartridge that performs well ballistically with great accuracy, has long barrel life and low recoil is the competitive shooter’s ideal. For the hunter, other factors may weigh more heavily.

    Efficient cartridges make excellent use of their available powder and case/bore capacity. They yield good ballistic performance with relatively little recoil and throat erosion. A classic example in the author’s experience involved a featherweight 7x57mm hunting/silhouette rifle. When loaded to modern-rifle pressures, just 43-44 gr. powder pushed a 139 gr. bullet at 2900 fps from its’ 22” barrel. Recoil in this light rifle was mild; it was very easy to shoot well, and its performance was superb.

    An acquaintance chose a “do everything” 7mm Remington Magnum… for use on medium game at short ranges. A larger, heavier rifle, it used ~65 gr. powder to achieve ~3200 fps with similar bullets -- from its’ 26” barrel. Recoil was higher, and he was sensitive to it, which hampered his shooting ability. (Note: an increase in powder weight adds significantly more recoil than the same weight would, if it were added to the bullet instead.) I.e., 20 gr. more powder increased recoil much more than a 20-gr. increase in bullet weight would. To this, add increased barrel heat and erosion, especially for competitive shooters.

    Similarly efficient calibers include the 6mm BR vs. .243, and others. Today’s highly-efficient calibers, such as 6mm BR and a host of newer developments might use, say, 28-30 gr. powder to launch a 105-107 gr. match bullet at speeds approaching the .243. The .243 needs ~40-45 gr. charges at the same velocity.

    Champion-level Long Range shooters need every ballistic edge feasible. They compete at a level where 1” more or less drift in a wind change could make the difference between winning and losing. Shooters recognized this early on -- the then-new .300 H&H Magnum quickly supplanted the .30-06 at the Wimbledon winner’s circle in the early days.

    The .300 Winchester Magnum became popular, but its 190-220 gr. bullets had their work cut out for them once the 6.5/284 and its’ streamlined 140-142 gr. bullets arrived on the scene. The 6.5/.284 gives superb accuracy and wind performance with about half the recoil of the big .30 magnums – albeit it is a known barrel-burner.

    Currently, the 7mm Remington Short Action Ultra-Magnum, a.k.a. 7mm R-SAUM, is giving stellar accuracy with cutting-edge 180-ish gr. bullets, powder charges in the mid-50’s gr. range and velocities about 2800+ fps in long barrels. Beyond pure efficiency, its’ modern, “short and fat” design helps ensure fine accuracy relative to older, longer cartridge designs of similar performance.
    Recent design advances are yielding bullets with here-to-fore unheard-of ballistic efficiency; depending on the cartridge, they can make or break ones’ decision. Ballistic coefficients (“B.C.” -- a numerical expression of a bullets’ ballistic efficiency) are soaring to new heights, and there are many exciting new avenues to explore.

    The foregoing covers a lot of ground very rapidly; each topic rates serious study by itself, but that’s not possible here. However, we hope that in mentioning these issues, newer handloader/ competitors will study them and increase their ability to assess calibers comprehensively.

    The ideal choice will likely be a carefully-considered balancing act between bullet B.C.’s, case capacity, velocity, barrel life and recoil. But, as with new-car decisions, choosing can be half the fun!
    Until next week, stay safe and enjoy the shooting sports!



    Beginning Handloading, Part 20 Checking Your Work:*Accuracy & Chronograph Testing


    Today, “Handloading Hump-Day” departs from handloading technique and theory to address the final result of our work. How does our ammunition perform? How well does it meet our specific needs? And, finally, how do we capture valid data for decision-making in our testing?

    Bench Testing Technique: Testing one’s rifle from a rest for accuracy can be fairly simple once the basic tenets are understood. However, it does require consistent, focused attention to detail. Knowing those principles and the essential details will help shooters to obtain their rifle’s best accuracy and to properly assess their ammunition.

    • A. Begin with the obvious – check tightness of all screws and fasteners such as action screws, scope base and ring screws, etc. This can also include parts of one’s rest equipment -- e.g., the main post of the typical benchrest pedestal. The author got “bitten” many years ago when accuracy testing his personal NM Beretta 92 with a series of carefully and laboriously constructed match loads, using his personal Ransom Rest. The pistol did not perform well with any ammunition tried and, in fact, shot much worse than expected. Several load combinations were tried, all with similar results. Belatedly, he checked the rest and found that a screw securing the rest to its’ base had come loose! All that tedious time spent at the loading bench was wasted! From that day on, the author began each pistol testing session with a group from his known-good “control” match handload, to verify that the system was working correctly.

    • B. Keep good records! Mark and label your test ammunition so that cartridges can be identified if a box should fall and get mixed up. This can prevent much needless confusion and suffering. Keep both ammo and test results well organized. Scrawled abbreviations on disorganized targets with incomplete data can be very hard to interpret, months after the fact. Instead, immediately measure groups and record them in a well-organized notebook or record system. This will ensure your components, loading and testing time will not be for naught. Several popular target measuring computer programs/apps are available. These record not only the load/firearm data, but retain photos of the targets with precision measurements illustrated. They are a great way to quickly and compactly organize and track your work. (Accuracy statistical procedures will be addressed in a future installment.)

    • C. Bench testing technique: Firing a rifle to obtain its’ maximum accuracy from a sandbag rest uses much the same theory as a quality machine rest. The key mantra here is **THE REST DOES ALL THE WORK.** I.e., the rifle should be fully supported by whatever rest/bag method you choose, and as little muscular effort as possible should be used to “steer” it or keep it on target.
      Obviously, the tensions of one’s cheek on the stock, butt against the shoulder, firing hand on the grip, etc. will differ when testing a .22 rimfire vs., say, a .300 WSM. Rifles generating more recoil require greater control for consistent performance. However, the key here is *consistency.* Learn and strive to always use highly consistent pressure on the grip, cheekpiece and buttstock for every shot to ensure accurate results. Set up the rifle so that the crosshairs are exactly on the aiming point when supported by the rest, without the shooter’s touching the rifle at all. That is the ideal. The shooter should exert as little muscular control over the rifle as possible to keep it on target during firing. Sub-optimal benches, rests or positions may require very slight adjustments to perfect the aim while testing. However, as much as possible, those adjustments should be made via the rest/bags. Upon firing, the rifle should slide straight to the rear in recoil. After firing, the rifle should be returned to its’ original position, crosshair alignment and bag stability checked, and the next shot is carefully taken. Early on, this may seem almost an excruciatingly slow process. However, with practice it becomes natural and one can do it quickly and efficiently, so don’t be discouraged. Note the details of the machine rest in Photo 1. This rest, designed and built by the USAMU’s Custom Firearms Shop (CFS), allows the rifle to track straight to the rear very precisely. Great care was taken to ensure that it had optimum, smooth and consistent resistance on the rails (below the bed) to dampen recoil uniformly. After firing, the rifle is carefully returned to the original firing position without handling it roughly or bumping it to induce vibration. This rest gives excellent results with a wide variety of rifles ranging from 5.56mm to large magnums. The straight-line tracking of this type rest is the goal for one to emulate when shooting from a bench. USAMU CFS Test and Handloading personnel also test rifles from various benchrest, bag and bipod setups at distances to 1000 yards and beyond. This is an important skill, which is perishable if not practiced periodically once it’s been finely developed.

    • D. What type rest is needed? Many shooters use well-built, adjustable “benchrest” style pedestals. (See Photo 2). These feature integral sandbags to support the forend, along with fine, lockable elevation adjustments. In addition, various “eared” type leather/cordura sandbags are used to support the buttstock. Having a precision rest, especially with an adjustable top that allows fitting the sides to each rifle’s forend, can greatly simplify testing. Moreover, a rear sandbag that matches the stock’s bottom contour well also helps streamline testing. Expensive equipment, however, is not a requirement. Excellent shooting can be done with simple canvas bags filled with sand, stacked and arranged to give stable, consistent support to the rifle. For decades, the ubiquitous home-made sandbags have employed empty 25-lb. birdshot bags, lined with plastic and held closed with a simple twist of wire. In this case, use a number of bags to build a sturdy, stable platform for the forend, rather than just a couple of bags stacked on top of each other. In the end, having a good understanding of the fundamentals, plus good technique helps far more than having expensive equipment without the skill to exploit it!


      This concludes Part 1 of this series. Join us again next week as we further explore ways to obtain the best accuracy when testing rifles and ammunition. Until then, be safe!




    Beginning Handloading, Part 22: Accuracy & Chronograph Testing, Part 3

    Welcome back to our weekly Handloading Hump-Day column! Today, we’ll explore basic aspects of testing with telescopic sights – i.e., optics. Our two prior columns (10 Nov.; 04 Nov.) detailed proper benchrest shooting technique, and may be helpful.

    One aspect which helps complete the previous 2 columns relates to making rifles with rounded forearms more stable on the bench.

    Benchrest Adapters for Non-Benchrest Rifles:
    As was mentioned previously, dedicated Benchrest rifle competitors use stocks with flat-bottomed forends which greatly increase their stability on the rest. Highpower, Service Rifle and Long Range rifles typically have round forends, making them more difficult to shoot super-accurately from the bench.

    This is due to a tendency to roll from side to side on the bags during aiming or recoil, and is especially prevalent with AR-15’s, due to their pistol grips being so far below the bottom line of the forend. This acts almost as a lever, and makes these rifles more sensitive to even slight technique flaws using the firing hand.

    Various firms make benchrest adaptors that fit a match rifle’s accessory rail or otherwise attach to AR-15s. These are nothing more than flat plates of about 2.5”-3.0” wide. They can be adjusted fore and aft to maximize stability on the bags, and they can be a great help. In addition, stock toe adapters are also available, especially for the AR-15, which provide a flat, wider surface for greater stability.

    Bench Testing Technique, continued:*

    Optical Sight Testing
    • (A). Correct Target Size and Magnification:
      Suit your target to the optics you are using. That is, if you are shooting a 4X hunting scope with medium/heavy crosshairs, then aiming at a 1” paster at 100 yards will necessarily introduce some inaccuracy.

      Typically, these crosshairs will cover the dot completely, and may even be significantly larger than the dot. If one can’t aim reliably at a fine point – i.e., moving ½” in any direction still allows covering the dot – then the problem of introducing spread into your groups becomes obvious.
      Pick a target size that works well for your magnification, reticle and distance. For scopes of ~9-12X, this author has found a 2", solid black square on a white or tan background to work well at 100 yards.
      He is able to quarter the square evenly with the crosshairs. He has no difficulty shooting excellent groups with this setup – 0.3 - 0.5 MOA consistently with various .308’s, etc., depending on the accuracy of the rifle.

      Depending on one’s eyesight and scope, some may prefer an orange target instead of black. If the scope allows it, some prefer to align the crosshairs with the vertical and horizontal edges of one corner.
      It's wise to try both methods. A very fine shooter of the author's acquaintance prefers this technique. Yet, in periodic tests over 30+ years, centering the square has consistently worked best for this writer.
      Jumping up to ~20-24X power, the typical 100-yard “Benchrest” target has worked well. This consists of a heavy-lined, 1” black square with a white center, plus thin scoring rings below it. These often come with 6 aiming marks on a single sheet of paper. This reduces the time and supplies needed for testing. (There are also scaled-up versions for 200 and 300 yards.)

      The extra magnification vs. a 10-12X scope means the shooter can resolve much smaller parts of the target. Depending on one’s eyesight, crosshairs, bench technique and general preferences, one can hold on the white center of the square, or on one corner as described above. Or, one may prefer the white center of the “bullseye” scoring rings below the square, etc.

      Whatever method one chooses, it is best to have the rifle zeroed ~1.0”- 1.5” away from the point of aim. A low point of impact is preferred; shooting high can put shots into the black square, where they can be hard to see.

      Shooting low offers the benefit of seeing and “calling” each shot as it is fired. Zeroing away from your point of aim avoids grouping bullets on the aiming point, making it ragged, indistinct or non-existent.
    • (B). Adjusting Crosshair Focus:
      Along with basic set-up of one’s equipment, it is important to focus one’s scope/crosshairs for one’s eyesight. This is also the time to adjust the scope’s parallax, which eliminates aiming error at one's exact target distance. These two topics can cause much confusion for the beginning shooter.

      To focus the crosshairs for one’s eyes, quickly aim the scope at a blank, featureless surface – a wall, the sky, etc. See if the crosshairs are sharply focused and heavily black. It’s very important to do this within only a few seconds of starting to view through the scope.

      The eye naturally tends to accommodate and adjust its focus to make the crosshairs sharp. The goal is to see the crosshairs in focus instantly, without having to adjust the eye.

      It’s best to check this several times, to start. After moving the scope away from the eye, look at a distant object before returning the scope for another quick look. If the crosshairs are verified to be in-focus, no further action is required.

      If they are not, the focus adjustment is on the REAR lens – the ocular lens. Many scopes secure the eyepiece adjustment via a lock-ring jammed against it. This ring must be loosened to begin adjustments.
      The easy method is to screw the eyepiece assembly out (to the rear, or counter-clockwise), away from the ring. Move the lock ring forward for clearance, and begin turning the eyepiece in ½ turns in 1 direction. Make frequent, quick checks on the crosshair focus. If they get fuzzier, reverse directions and repeat.

      Once the crosshairs are in sharp focus instantly when viewing against a blank surface, secure the lock ring. Scopes with improved ergonomics may have a readily adjustable eyepiece without a lock.
      These typically feature a rear adjusting ring that rotates smoothly to set the crosshairs focus. They also often feature a “+/-“ scale to help measure and repeat settings. While this simplifies the operation, the principle is the same.
    • (C). Parallax Correction
      Next, we move to parallax. In layman’s terms, this causes the apparent shift of the crosshairs against a fixed aiming point when moving one’s eye around behind the eyepiece. Place the rifle on the rest and settle the crosshairs on an aiming point at one's target distance.

      Without touching the rifle, put your eye behind the scope. Move your head up, down, left and right within the limits of your ability to see through the scope. If there is no apparent movement of the crosshairs on the target, your scope is parallax-free at that distance. Crosshair movement indicates parallax.

      Most standard hunting scopes do not have adjustable parallax. They are set by the factory at a particular distance: usually 100-150 yards for centerfires, and 50-75 yards for quality rimfire scopes.
      With these, know that parallax effect is far more dramatic at ranges significantly *shorter* than the distance at which the scope is set, rather than farther away. Moreover, one’s natural tendency to use a consistent head position will help minimize parallax effect.

      Target scopes, or scopes with higher magnification, typically have parallax adjustment. Older or less-expensive scopes typically adjust via a ring around the objective lens bell. One will see distances such as “50, 75, 100, 150” etc. marked at intervals around the ring.

      Beware! *Many times, these seem to be for decorative purposes only, as they bear no meaningful relation to the actual firing distances!*
      One should always verify the parallax ring setting when the scope is parallax-free at one’s chosen distance. More recently, the better manufacturers have begun calibrating the distance on the ring to the actual, correct parallax setting. This certainly makes life easier for the shooter.

      Once one has checked a particular scope and knows how it functions, simply dial out the parallax whenever one changes shooting distances, for maximum accuracy. Newer scopes – particularly target or “tactical” models – increasingly feature a side parallax adjustment knob opposite the windage knob. This facilitates making adjustments easily from field or bench positions.



    Thus ends Part 3 of our series on Accuracy Testing and Chronographing. Next week, we will further discuss the use of optics, including verifying adjustment increments, effects of increased magnification, and mirage.

    Until then, stay safe, and enjoy the shooting sports!




    Beginning Handloading, Part 23: Accuracy & Chronograph Testing, Part 4

    Handloading Hump-Day returns! This installment will further explore aspects of optimizing one’s optics for accuracy testing. Our previous column (18 Nov.) addressed scope magnification, proper target size, crosshair focus and parallax. It may be useful to those who missed it.

    Optical Sight Accuracy Testing, continued:

    [list](A). Elevation and Windage Adjustment Verification:
    One basic rule to remember in shooting is, “I don’t *know* what I THINK, I only *know* what I MEASURE.” That is, your scope literature may say it has 0.25 MOA clicks, but until you verify it, that’s an unknown.

    This author has seen target scopes with >0.35 MOA clicks, that were advertised as having 0.25 MOA adjustments. Take nothing for granted! One older target scope that had been sent back to the factory for updated knobs returned with 0.43 MOA clicks! Needless to say, before it was discovered, getting a 1000-yard zero was a nightmare!

    Obviously, as ranges increase, the number of clicks needed to zero by trajectory data does also. This disparity (0.25 vs 0.37 MOA) accumulates, and point of impact increasingly wanders away from the desired area. This has been known to lead to frustration, confusion, and in severe cases, perhaps even vile language (but, never here at the USAMU, of course!)

    To quickly check one’s scope, fire a group from the bench at 100 yards, and then adjust the scope “up” 20 MOA. Fire another group at the same aiming point as before, and then measure the distance between groups. It should be close to 20.0” with most MOA scopes.

    One beginning 1000-yard shooter’s personal target scope only moved the second group 17”! A new click-value was calculated for his scope, and he then calculated correct elevation adjustments for 600 and 1000 yards. Once zeroed at 600 yards, he adjusted for 1000 yards. He used his calculated click-value with data from his bullet maker’s ballistic tables, at his chronographed velocity. His first shot ever at 1000 yards hit the 10-ring!
    [*](B). Nuances of Scope Magnification:
    Eventually, the question arises: “What power scope should I use?” With excellent technique and some practice, shooters can group very well at 100, 200 yards and beyond with a 9-10X scope, always adjusting the aiming mark to suit their magnification and crosshairs at each distance. Greater power means greater resolution, or the ability to aim at a smaller part of the target.

    Moreover, it helps one see any movement of the rifle on the bags easier, and thus fine-tune one’s technique to better remove the inconsistency. For general testing, ~20-24X can serve quite well. However, when bumping up to, say, 36X, one sees every little tremor -- much more dramatically than at 24X. One’s heartbeat may become very evident through the scope.

    What can be seen, can be adjusted for – one modifies the bench technique to reduce movement, resulting in maximum accuracy. This is an illustration of the oft-quoted popular movie line, “Aim small, miss small.”

    Shooters who are already accustomed to high power optics usually find a significant increase to be a boon. Those coming from, say, 4x – 10X straight to 36X may find that this slows their shooting significantly until they learn to fully stabilize their rifles on the rest.
    [*](C). Mirage:
    Finally, there is mirage. This may be mirage out on the range itself, which can be helpful in wind reading, or mirage seen in one’s scope due to barrel heat.

    Mirage can cause problems of an indistinct aiming point, or shifting of the apparent aiming point away from the actual location on target. This grows worse (I.e., more visible) as magnification increases. Range mirage occurs when heat rises from the ground, and it can be especially difficult in hot, humid conditions and when firing prone.

    Getting out of prone and onto a bench can help reduce the effects of ground mirage. Lowering the magnification on a variable-power scope can also sometimes improve one’s ability to cope.

    A “mirage band” is often used by Match Rifle shooters. This is a cloth or elastic strip about 2” wide that runs from the receiver, under the objective lens, and out to the muzzle.

    Its purpose is to divert barrel mirage out to the sides of the band and away from the scopes’ optical path. In severe cases, mirage may rise from the muzzle, even when using a band, and thus distort the target image. Even a little wind is excellent for dispersing mirage due to barrel heat.

    This concludes Part 4 in our series on Accuracy Testing and Chronographing. Next week, we’ll explore the use of iron sights during accuracy testing. Until then, good luck, stay safe, and good shooting!



    Beginning Handloading, Part 24: Accuracy & Chronograph Testing, Part 5

    As promised, Handloading Hump-Day returns! In this installment we’ll discuss the specialized aspects of using iron sights for accuracy testing our ammunition.

    Accuracy Testing: Iron Sights:
    For various reasons, a competitor might elect to test his rifle/ammunition’s accuracy with iron sights instead of optics. By “iron sights,” of course we mean aperture rear sights, not the barrel-mounted sporting, buckhorn, etc. sights found on hunting rifles.

    While these can get the job done in hunting, they are vastly inferior to a quality peep sight for precision shooting. Some rifles may be difficult and/or expensive to scope, such as a NM M1A (relative to, say, a NM AR-15.) Even when scoped, some rifles require such high or awkward head positions that shooting them extremely well becomes a challenge.

    On the other hand, a good number of die-hard Service and Match Rifle shooters don’t practice or test much with optics or from a shooting bench. That is an acquired skill in itself, as we outlined in the several previous chapters. Thus, they may be very comfortable testing with iron sights – whether from the bench or prone with a sling.

    It’s important to realize that when choosing to test with iron sights, certain complexities will be introduced that were not present with a scope. Moreover, one advantage of the telescopic sight is lost – magnification, and with it, finer resolution and the ability to see rifle unsteadiness on target and eliminate it.


    Nuances of Testing With Iron Sights

    In previous chapters we detailed methods to remove parallax effect on our accuracy with a scope at our given target distance. Iron sights require a very consistent head position on the rifle stock, much like a scope that’s not properly adjusted parallax-free.

    Changing head height, angle, cheek pressure on the stock, eye relief, etc. from shot to shot can introduce inconsistencies that increase our group size. For this reason, it’s good to avoid any actions that cause a shooter to unnecessarily break his position during a string of shots, such as reloading when not required, roughly working a bolt-handle and disturbing the position excessively, etc.

    When shooting with a scope, one is primarily concerned with sight, PICTURE -- i.e., where the crosshairs are placed on the target. One works to maintain that point of aim precisely without disturbance due to breaking the shot.

    With iron sights, one now introduces a new element: sight ALIGNMENT. This refers to the precision placement of the front sight in relation to the rear sight, be it a post front sight in the center of an aperture rear sight, or aperture front and rear sights.

    Sight picture is still important, but sight alignment is critical. With perfectly aligned sights, the sight picture can be off a surprising amount and the shooter can still get a “10” or “X”, depending on target size and discipline. With a perfect sight picture but imperfect sight alignment, the shot is likely to stray far afield.

    Thus, one must balance these two functions while shooting and ensure sight alignment is excellent-to-perfect for every shot. This requires changing the eyes’ focus – from aligned sights/target (sight picture) to aligned sights with focus on the front sight (sight alignment. This is because the eye can only focus precisely on 1 thing at a time. That one thing needs to be the front sight when the shot breaks, for best results.

    Eye fatigue is another variable which becomes more important during iron-sight testing. The eye can only maintain precision focus for a limited period. One must be careful not to exceed the eye’s
    capability, or poor shots will result. Resting the eyes between groups or even shots – changing the focal distance, looking at a green, wooded area, etc. can help one get optimal performance.

    As we detailed previously, it’s very important to match one’s target type/size to one’s iron sights. The author has seen countless people attempting to shoot at orange, 1” or 2” squares/circles at 100 yards with battle rifle or hunting sights that are much larger than the target. This virtually guarantees frustration.

    In the author’s view, anything that draws the shooter’s attention AWAY from sight alignment, and TOWARDS sight picture introduces the risk of inaccuracy. A tiny target perched in the exact center of a very wide front sight blade makes the shooter work to keep that target precisely on the centerline of the front sight. As the eye can focus on only one thing at a time, this naturally draws effort/attention away from sight alignment and error can creep in.

    Choose a large, distinct (i.e., black, heavily contrasting) target so that one need not be overly concerned with sight picture once it’s been correctly obtained. This lets the shooter attend more to sight alignment, which is critical.

    This concludes Part 5 in our series on Accuracy Testing and Chronographing. Next week, we’ll further explore aspects of precision testing using iron sights, such as point of aim (center hold, six o’clock, line-of-white), optimal dimensions for sights, effects of light on testing, shooting from position vs. a benchrest, and statistics, among others.

    Join us again soon, and stay safe!



    Beginning Handloading, Part 25: Accuracy & Chronograph Testing, Part 6

    Welcome back to the U.S. Army Marksmanship Unit’s series on beginning handloading! Today, we conclude our discussion of accuracy testing Service and Match Rifles using iron sights.

    Last week (02 Dec. 2015), we discussed several topics including the background and theory of testing with iron sights, the importance of sight alignment vs. sight picture and selecting optimum target sizes to facilitate accuracy in testing. Next, we’ll cover aspects of the aiming method.

    Point of Aim: Center Hold, vs. 6 O’Clock, vs. “Line of White,” vs. …
    Individual shooter’s preferences vary re: their hold method – i.e., where they aim on the target. Part of this is related to their eyesight, and part may be related to their training, especially for offhand and rapid-fire. Some shooters feel very comfortable in offhand and rapid-fire when holding in the center of the black.

    This hearkens back to the “sight alignment vs. sight picture” emphasis. If their eyesight allows them to distinctly see the front sight post against the relatively fuzzy aiming black, then with properly-aligned sights, any shot fired while within their minimum arc of movement – and while in the black – will be a good shot. This allows them to work more on sight alignment and less on sight picture. It can also help speed recovery between shots during rapid-fire (especially important with rifles of heavier recoil.)

    Others, whether due to eyesight that requires a sharp contrast between the target and the front sight, or due to training preferences, use a six o’clock hold. Here, the top flat of the post front sight is placed exactly at the bottom edge of the aiming black, which gives a very precise aiming point. Some are comfortable with this method in offhand, rapid-fire, or both, and find it improves their precision.
    Still others prefer a “line of white” hold, which allows a thin, consistent line of white between the top of the front sight and the bottom edge of the black. This helps avoid a tendency of the front sight to creep up into the black slightly, unnoticed.

    When shooting from the bench, it may be very easy to get an excellent sight picture with high contrast between the front post and the target using the six o’clock hold or line of white. Without the rifle’s moving due to shooting from position, the bench’s steadiness may make this preferable vs. a shooter’s normal hold in competition.

    Experimentation with methods to determine what works best is helpful. Whatever method one uses, it is very important to do things consistently every time. Eye relief, placement of the head on the stock and pressure of the cheek on the comb are all important, in addition to the other technique factors discussed earlier in this series.

    One’s choice of iron sight dimensions – both aperture (front and rear) and Service Rifle sights (post width, rear aperture diameter) is highly personal and much depends on the shooter’s eyesight. Early in his Service Rifle career, this writer took his rifle to a 100 yard range and set up a correctly-scaled 100-yard reduced target. After firing 8 groups with match ammo from the bench using a full-width NM front sight, he installed a 0.020” narrower front sight. After resting a bit, 8 more groups with the same ammunition proved very instructive.

    The two 8-group averages were identical to within 0.1”. However, the author had to work much harder to focus on the narrow front sight, which would contribute to eye fatigue and distraction. From then on, he used the standard-width NM front sight with good results. Other members of his team, blessed with eagle-like eyesight, preferred the narrower sights and performed extremely well with them.
    Due to the effects of light on the sights, it’s important to blacken the front and rear sights to prevent glare and glint. This can be done with commercial sprays, an old-fashioned carbide lamp, or even the smoke from a burning MRE spoon (field expedient!). If possible, shooting under overhead cover also improves consistency, helping prevent variable light conditions on the sights that would affect accuracy or changes in sight picture.


    Testing From Position Rather Than the Bench
    Any number of rifle competitors shoot so much from position, and so little (or never) from a bench, that they are not comfortable managing the rifle on a benchrest. These shooters may have such confidence in their ability to shoot consistently and accurately either from a sling, prone, or with a sling and front sandbag, prone, that they prefer this to using a benchers.

    If capable of meaningfully testing their rifle and ammo’s accuracy, this is perfectly fine. However, for those comfortable with it, bench testing allows shooters whose sight alignment and position skills aren’t as advanced to do good work also.


    Statistics: Group Sizes, Distances, Sample Sizes
    How many groups should we fire, and how many shots per group? These questions are matters of judgment, to a degree. First, to best assess how one’s ammunition will perform in competition, it should be test-fired at the actual distance for which it will be used. I.e., 600 or 1000 yard ammo should be tested at 600 and 1000 yards, respectively, if possible. It is possible to work up very accurate ammunition at 100 or 200 yards that does not perform well as ranges increase. Sometimes, a change in powder can correct this and produce a load that really shines at longer range.

    The number of shots fired per group should be realistic for the course of fire. That is, if one will be firing 10-shot strings in competition, then final testing, at least, should involve 10-shot strings to reflect the true capability of the rifle. Knowing this will help the shooter better decide in competition whether a shot requires a sight adjustment, or if it merely struck within the normal accuracy radius of his rifle.
    Many years ago, the author met a shooter who gleefully spoke of his “half-minute accurate M1A.” As this would have been a rather fine and rare specimen, the author inquired further. The shooter then retrieved a small group from his wallet… consisting of only 3 rounds fired!

    He enjoyed deluding himself about the true accuracy of his M1A, certainly. However, this didn’t help him on the range when he had decisions to make based on knowing the rifle’s actual capability.
    Finally, how many groups should be considered a valid test? Here, much depends on the precision with which one can gather the accuracy data. If shooting from a machine rest in good weather conditions, two or three 10-shot groups at full distance may be very adequate. If it’s windy, the rifle or ammunition are marginal, or the shooter is not confident in his ability to consistently fire every shot accurately, then a few more groups may give a better picture of the rifle’s true average.


    Elevation and Windage Adjustment Verification

    It is just as important to verify the true value and repeatability of one’s peep sight adjustments as it is to verify those of a scope. This can be done using a quality dial indicator to track the aperture’s movement with the rifle held steady in a fixture or vise. Test the elevation and windage adjustments, looking for uneven click values and for “dead” clicks that don’t affect the zero as expected.

    Likewise, check for sight backlash, in which the shooter adjusts the sight back to a previous position, but the clicks don’t give the correct value upon reversing. Small, preliminary steps such as these can prevent a tremendous amount of frustration and head-scratching on the range.

    With iron sights, the sight radius – i.e., the distance from front to rear sight – affects the click value. Thus, it is entirely possible for one match aperture sight to have ¼, 1/3, or even ½-minute of angle adjustments, depending upon how far apart the sights are mounted. Sight manufacturers provide information on the ideal distance between sights to produce the desired fineness of adjustment. When acquiring a rifle that’s been already built, this should be taken into consideration.

    Thus ends Part 6 in our series on Accuracy Testing and Chronographing. Next week, we’ll explore using chronographs to measure bullet speed and obtain useful trajectory and wind data for our ammunition. Until then, stay safe and enjoy the shooting sports!



    Beginning Handloading, Part 26: Accuracy & Chronograph Testing, Part 7

    Welcome back to the U.S. Army Marksmanship Unit’s series on beginning handloading! Today, we resume our discussion of testing handloads for Service and Match Rifles. Recent topics included the background and theory of testing with scopes and iron sights, the importance of sight alignment vs. sight picture and choosing optimum target sizes for best accuracy in testing.

    Then, we covered various aspects of the aiming method. Those who missed these earlier posts may find them helpful. A brief review from our most recent post on accuracy testing, reprinted below, will set the stage re: chronograph sample sizes.


    Statistics: Group Sizes, Distances & Sample Sizes
    How many groups should we fire, and how many shots per group? These questions are matters of judgment, to a degree. First, to best assess how one’s ammunition will perform in competition, it should be test-fired at the actual distance for which it will be used. I.e., 600 or 1000 yard ammo should be tested at 600 and 1000 yards, respectively, if possible.

    It is possible to work up very accurate ammunition at 100 or 200 yards that does not perform well as ranges increase. Sometimes, a change in powder type can correct this and produce a load that really shines at longer range.

    The number of shots fired per group should be realistic for the course of fire. That is, if one will be firing 10-shot strings in competition then final accuracy testing, at least, should involve 10-shot strings. These will reflect the rifles’ true capability. Knowing this will help the shooter better decide in competition whether a shot requires a sight adjustment, or if it merely struck within the normal accuracy radius of his rifle.

    How many groups are needed for a valid test? Here, much depends on the precision with which one can gather the accuracy data. If shooting from a machine rest in good weather conditions, two or three 10-shot groups at full distance may be very adequate. If it’s windy, the rifle or ammunition are marginal, or the shooter is not confident in his ability to consistently fire every shot accurately, then a few more groups may give a better picture of the rifle’s true average.


    Initial Chronograph Setup
    A chronograph is an instrument designed to measure bullet velocity. Typically, the bullet casts a shadow as it passes over two electronic sensors placed a given distance apart.

    The first screen is the “start” screen, and it triggers an internal, high-speed counter. As the bullet passes the second, or “stop” screen, the counter is stopped. Then, appropriate math of time vs. distance traveled reveals the bullet’s velocity. Most home chronographs use either 2-foot or 4-foot spacing between sensors. Longer spacing can add some accuracy to the system, but with high-quality chronographs, 4-foot spacing is certainly adequate.

    Laboratory chronographs usually have 6 feet or more between sensors. Depending upon the make and model of one’s chronograph, it should come with instructions on how far the “start” screen should be placed from one’s muzzle.

    Other details include adequate light (indoors or outdoors), light diffusers over the sensors as needed, and protecting the start screen from blast and debris such as shotgun wads, etc. When assembling a sky-screen system, the spacing between sensors must be extremely accurate to allow correct velocity readings.


    Preliminary Load Development and Velocities
    When developing a load for one’s firearm, a chronograph is a very useful tool. Naturally, it tells the bullet speed, allowing ballistic calculations for wind deflection and trajectory, as well as velocity variation. It can also be used, in conjunction with recent handloading manuals, as an indirect indicator of pressure.

    Differences between individual barrels, chamber throats, and powder lots, plus many other variables, can cause results to differ from those cited in the manuals. Thus, beware the notion of a “magical high-speed barrel.”

    Suppose the manual states that their 26” .260 barrel achieved 2900 fps with X bullet, Y powder, Z case and W primer. If you achieve that speed with identical components in *your* 26” barrel while using 5 grains less powder, that should raise a red flag.

    Pressures may be at or near maximum in your rifle, despite the higher “maximum” charge cited in the manual. Observe for pressure indicators as discussed in your manuals, and never exceed published maximum powder charges.

    When working up a potential match load for your rifle, it is wise to survey at least 2-3 current factory sources of data for your powder/bullet combination. This will give you a sense of the variations possible due to random factors. Then, beginning at a safe, listed “starting” powder charge, work your way up in increasing powder increments while shooting over the chronograph. Also, assess your brass and rifle for signs of increasing pressure.

    What size powder increments should be used? This depends on the case volume and powder chosen. A 0.3 grain or 0.5 grain increase in powder charge may be significant in a .223, but of little consequence in a .300 Magnum. Faster burning powders are more sensitive to small changes in powder charge, increasing pressures more rapidly than slow-burning powders. For .308-sized cases, 0.5 grains is a safe increment until one nears maximum pressures.


    Chronograph Sample Sizes
    How many shots should one fire to obtain an accurate velocity for each powder charge increment when loading? That depends in part on the uniformity of velocities given by your particular powder/bullet/barrel combination.

    For example: a 3- or 5-shot sample gives an extreme spread (ES) of 140 fps between the high and low velocities recorded. The lack of uniformity indicates that firing 1 or 2 shots over the chronograph to check a powder charge is likely to give a wide margin of error.

    In such a case, larger sample sizes will give a better idea of the true, average velocity. While approaching the loading manual’s listed maximum charge, track the ascending velocities per charge increment. One may well see that as charges approach maximum, velocities may become much more uniform. Moreover, velocity gains per increment of increase often become smaller.

    Ideally, one won’t encounter velocity variations this large; changing primers and/or neck tension may increase uniformity. If wide variations persist, however, a different powder may offer great improvement.

    Consider this: a 2-shot scan gives double the data of a one-shot sample. A 4-shot sample gives twice the data of a 2-shot scan. Larger samples are particularly useful if there is much velocity variation in the population.

    On the other hand, one might already be familiar with a particular powder/bullet combination in one’s barrel. If it is known to have little variation, a 1 or 2-shot scan in the early stages while working up toward the maximum can be useful, while saving expensive bullets.

    As powder charges approach their maximum, some like to test accuracy while shooting over the chronograph. Although it’s a bit trickier to set up the bench, chronograph and target, this does yield more data per bullets expended. In such an instance, 5-shot or even 10-shot groups may be desirable at times.

    However, once one arrives at a load combination intended for competition use, one should chronograph at least a 10-shot sample. This gives a reasonable picture both of the load’s uniformity and its average velocity. For long range use, a 20-shot sample of one’s finalized match load is even better. This accurately shows the uniformity of one’s velocities over time. It is more likely to reveal any rare shots that develop velocities significantly different from the average.

    Thus ends Part 7 in our series on Accuracy Testing and Chronographing. Next week, we’ll conclude our section on Chronograph Testing. Until then, stay safe and enjoy the shooting sports!



    Beginning Handloading, Part 27:Accuracy & Chronograph Testing, Part 8


    Welcome once again to the U.S. Army Marksmanship Unit’s series on beginning handloading! Today, we will conclude our discussion of chronograph testing and evaluating handloads for Service and Match Rifles. The previous post of 06 Jan. 2016 provided much background information for this week’s column, and may be helpful to review for those who missed it.

    Modern chronographs usually calculate a wide variety of statistics for each sample, including the velocity Average (mean), Extreme Spread (ES, or the difference between highest/lowest velocities) and Standard Deviation (SD). Standard Deviation is probably the least widely-understood of these.

    Essentially, SD is a numerical reflection of how much individual velocities vary around the mean. Higher numbers equal more variation in individual shots, and lower numbers indicate less variation. However, there is a catch: for the SD to be valid, the sample size must be adequately large.

    Reaching back several eons to a misguided youth spent studying Statistics, the sample size greatly affects the accuracy of the SD’s prediction. In academic or industrial QC statistics, sample sizes tend to be rather large – many more than is practical for most NRA Highpower competitors. (A minimum sample of 30 is strongly preferred.)

    Within the marksman’s practical limits of, say, 20-shot or 10-shot samples, the SD can help one assess and compare the velocity uniformity of different loads. (Obviously, 20 is significantly more predictive than 10.) However, with a 5-shot, or especially a 3-shot sample, the SD generates little hard information; the sample is too small to adequately reflect the load’s population of potential shots to be fired.
    Consider this string of 10 velocities from Rifle X, fired from a cold, fouled bore as is frequently done in NRA Highpower competition: 2829, 2936, 2788, 2830, 2841, 2803, 2801, 2835, 2837, 2836. If one sampled only the first 3 shots, much variation would exist: ES = 146 fps, and the average = 2851 fps.

    If one’s random sample happened across the last 3 shots to be fired, however, the load would look great -- on paper! (ES = 2 fps!) The average, 2836 fps, is not far from the first sample’s average, but the superb uniformity demonstrated in this 3-shot sample would be very misleading.

    When considering the entire, 10-shot sample, one finds the ES still = 146 fps, the SD = 40, and the 10-shot average = 2830. Another load with a much lower ES and SD would be preferable, assuming accuracy met the required standard. Extremely uniform velocities alone are *not* a reliable predictor of accuracy!

    Readers wishing to learn more about using SD to evaluate their load’s shot-to-shot consistency might search the internet for a brief tutorial. When used properly, SD can be a valuable tool. For approximately “normal” (bell-shaped) distribution curves, a rule of thumb is that ~68% of shots will fall within +/- 1 SD of the mean, ~95% within +/- 2 SD’s, and essentially all will fall within 3 SD’s of the mean.

    Thus, if one’s average velocity is 2700 fps with a (valid) SD of 10, ~68% of shots should fall between 2690-2710 fps, and ~95% within 2680-2720 fps. A different rule applies to ANY set of data, even those with a non-standard distribution. That approach (beyond the scope of this discussion), while not as precise, still allows prediction of ~75% of shots within +/- 2 SD’s of the mean.

    Once one has determined that their load is (A), sufficiently accurate at the target distance and (B), that velocity and uniformity meet the desired goals, the chronograph provides still more useful data. It allows the shooter to predict wind deflection (based on the bullets’ Ballistic Coefficient), trajectory and even remaining energy at various distances if desired. As with a rifle/load’s accuracy evaluation, these predictions should be verified by firing at the actual distance, to avoid unexpected surprises.

    The further the target distance becomes, the more challenging predicting ballistic effects such as wind deflection and drop (with precision) can become. What is easy at 600 yards becomes noticeably trickier at 1000 yards (+).

    As a young man, the writer was one of very few shooters to own his own chronograph (back in the Dark Ages). At that time, having the ability to actually measure one’s velocity, rather than having to guess, was simply revolutionary! Although generations of handloaders did rather well without them, once one has used a chronograph, loading without one would seem primitive and imprecise, at best.


    AND NOW, ONE FINAL RULE:

    Don’t shoot your chronograph!! (Yes, really!) The author has personally witnessed gruesome chronograph deaths several times at the hands of even experienced shooters. It is not a sight for the faint of heart.

    They simply fell victim to a few common pitfalls. It is very easy to become distracted when shooting over a chronograph for the first few times. Losing track of where the sights are, relative to the muzzle, can be hazardous for your sky-screen’s health.

    Remember, there is a significant offset between the muzzle and the sights/crosshairs at short range. When in doubt, err on the high side – i.e., shoot a bit higher than one thinks might be optimum for sensor readings. Firing ammunition without getting a reading is a lot less expensive (and embarrassing!) than replacing sky-screens!

    Many chronographs have light-diffusing shields supported about 10” above the sensors by two angled holders in the shape of a large “V”. Especially when using a scope of medium-high magnification, it can be startlingly easy to shoot these supports.

    If one’s magnification is high enough and parallax is not set for short range, the supports can be virtually invisible in the field of view. Experienced chronograph users often adjust the scope to its lowest magnification and parallax to its’ shortest setting. This makes the supports plainly visible in the field of view, and helps considerably.

    Also, pick an appropriate aiming point on the target or backstop. This helps ensure bullets cross the sky-screens along a consistent path and well away from the downrange apparatus. Finally, before firing the first shot, it is helpful to leave the rifle on the rest, aimed at one’s mark on the backstop, and view the bullet’s flight path from the side. Is it too close to the screens? If so, aim higher.

    This concludes our series on Accuracy Testing and Chronographing. Join us again next week for more helpful handloading information!
    Last edited by LittleLebowski; 02-07-2017 at 11:15 AM.

  2. #2
    Thank you for posting this.

  3. #3
    Bad guide, even worse mod LittleLebowski's Avatar
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    Quote Originally Posted by 1slow View Post
    Thank you for posting this.
    More coming!

  4. #4
    Thanks LL!! Love the post eventhough I'm less than half way through it.


    Sent from my iPhone using Tapatalk
    Using Tapatalk

  5. #5
    Site Supporter SeriousStudent's Avatar
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    This is very useful. Thanks for putting this together.

  6. #6
    Bad guide, even worse mod LittleLebowski's Avatar
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    Updated, more coming.

  7. #7
    PF Justice Warrior Chance's Avatar
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    Awesome! Thanks for putting this up.
    "Trying is the first step toward irritating those around you who know better." - @angry_prof

  8. #8
    Bad guide, even worse mod LittleLebowski's Avatar
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    More updates posted, I apologize for the lack of pictures, I hope to track them down once I'm finished transcribing and formatting the text.

  9. #9
    Member pdb's Avatar
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    Superb stuff. FWIW, the o-rings you want for your die bushings are #17: https://www.amazon.com/dp/B000L89BAQ/

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