Reloading 101 Question

[ccmdfd]

After many years of contemplating, I finally took the plunge and purchased some reloading equipment. I have a lot of potential projects, but right now want to concentrate on one.

The goal: Develop a load for my 7mm-08 with a Barnes TTSX that is effective for deer sized game 300 yrds and in.

Why? I've been shooting Barnes factory TTSX's for quite some time and have been impressed with the terminal performance on deer. However, I've never been impressed with the factory loaded ammo's accuracy. I'd like both. I'd be satisfied with <1 moa, and absolutely tickled pink with 0.5. Don't need anything better than that.

So I've purchased several reloading manuals, and watched dozens of hours of YT vids about reloading and felt like i could take a shot at it.

Got some brand new Nosler brass (all that was available), Federal Match LR primers (again all that I could find), TTSX bullets and Varget. Why Varget?-well 1. available, 2 I see it in many other calibers reloading data so I don't need to purchase a ton of different powders now, 3. Temp stability. It can be 90F on opening day and 20F on last day.

Read the Barnes manual, placed the bullets 0.05 off of "jam" as determined by the Hornady tool, and made up some ammo for charge weight testing. Started at min, loaded 5, then increased by 0.5 grain all the way to max (well the last was only a 0.4 change per their recommended max load), 5 rounds at each load weight.

Shot a group at 100 yards for each loading (10 total loadings of 5 each) with 10 min of cool down between loadings. Used LabRadar for chrono.

Why 100 yrds? I'm not an expert shooter. At 200 or more yards my inaccuracies would blow out any differences in the actual ammo.

What I observed:
1. I never found a plateau in velocities. There was a nearly perfect 30 fps increase for each 0.5 additional powder. Smallest delta for fps was 28, largest 44, most were mid-30's. (or do i have the wrong perspective? is a 28 an actual plateau??). FPS's ranged from 2666 to 2964.

2. Only the max load and max-.4 loads gave velocities similar to factory Barnes ammo out of the same gun.

3. I know i'm a newb, but i've looked at every video and webpage i can and i didn't see anything like a classic pressure sign even at max load.

4. Groups got smaller, then larger, then smaller, then larger. But my inaccuracies again come into play. I had 3 loadings in a row with what started as sub 1inch groups, but then 1 pulled shot taking it to a 1.5 inch group.

So big question: where to go from here??

As I see it I could:

1. Work with what I have. Go back to those smaller group sized loads and load some more and maybe even do some smaller variances between loads, say 0.3 grain and verify that there is indeed a node in that area. However-that general area is running 120 FPS slower than factory loads. Would that make a difference in terminal performance of the bullet?

2. Keep pushing up on the powder load until i get pressure signs, or find a definite node, or max out the case.

3. Since i didn't see any pressure signs at max load, just choose that even though it wasn't the smallest group so i can retain the FPS needed for performance, and then see if changing bullet seating would get the accuracy better.

4. Wide open to any other suggestions.

Any good reloading forums? Hate to join more and more internet stuff but if there's one which is considered the cream of the crop, then I 'd potentially join and ask there.

Thanks
cc

[Clusterfrack]

@JCL? Any ideas?

[walker2713]

If you mentioned it, I missed it….

Thanks,

George

[pyrotechnic]

I would load to the velocity you would like to achieve (within safe pressures) and then try some seating depth changes. Berger has a good article on seating depth on their website. Small sample sizes can tell you something it bad but can't really tell you something is "good". If something sucks and the rifle is known to shoot well changing powder has made the most difference for me in my experience.

The "flat velocity node" is mostly likely a myth. People that use that method are looking at single data points that ly within the ES of that particular charge weight. At least I have yet to see anyone produce a velocity "node" that is repeatable.

@Molon probably knows something about working up a load that will consistently perform. Hopefully he'll chime in. I'm just finding more and more that alot of our "reloading knowledge" is a lot of anecdotal evidence based on incredibly small sample sizes and we've somehow managed to made decent ammo despite and not because of our load development methods.

[ccmdfd]

If you mentioned it, I missed it….

Thanks,

George

D'oh!

120 TTSX

[psalms144.1]

When I was loading 7-08 for accuracy, I found that the single most important factor in getting tiny groups was seating depth. Generally, as long as it will fit into my magazine (internal or detachable), I found it couldn't be seated too long.

The best way to accomplish this is to get a cartridge overall length gauge, a caliber specific insert, and push your TSX all the way out until it JUST touches the lands in your barrel, then back off that measurement by a couple of hundredths of an inch. If that OAL will fit into your magazine, you're golden.

Once you have OAL noodled out, I'd load powder charges in .5 grain increments. Best load will likely fall somewhere between two of those charges, but you don't want to waste a lot of bullets, powder and time testing .1 or .2 changes.

FWIW, just by adjusting the OAL on my last 20" 7-08 "mountain rifle," I was able to take my standard hunting load - a 1.25-1.5 MOA load, and cut it in half.

[EMC]

It's pretty simple, you want to find the load that gives you the best repeatable group size with the lowest SD with an acceptable avg velocity that is safe.

[RevolverRob]

Let's go back to basics. Your first job is to duplicate the Barnes load. Why? Because it is a known entity to you. You know how that load shoots in your gun. Duplicate it first so that you can establish that you've got a clear understanding of all the core elements of making a 7mm-08 round. If your 7mm-08 Barnes Duplicate duplicates Barnes factory - then you have something to fine tune.

THEN you want to adjust your parameters, one parameter at a time.

If Seating Depth seems to be a a key component. Start either as long as possible or short as possible and you'll need to do lots of 20 rounds, not ten. Ten gives you just enough data to not tell you much, but make you think you are learning something. 5 rounds can't even give you a good SD estimate.

If you can duplicate the Barnes load - you can dial in the accuracy you want from there by fine tuning parameters one at a time (I bet you get where you want to be by merely adjusting seating depth.

[okie john]

After many years of contemplating, I finally took the plunge and purchased some reloading equipment. I have a lot of potential projects, but right now want to concentrate on one.

The goal: Develop a load for my 7mm-08 with a Barnes TTSX that is effective for deer sized game 300 yrds and in.

Why? I've been shooting Barnes factory TTSX's for quite some time and have been impressed with the terminal performance on deer. However, I've never been impressed with the factory loaded ammo's accuracy. I'd like both. I'd be satisfied with <1 moa, and absolutely tickled pink with 0.5. Don't need anything better than that.

So I've purchased several reloading manuals, and watched dozens of hours of YT vids about reloading and felt like i could take a shot at it.

Got some brand new Nosler brass (all that was available), Federal Match LR primers (again all that I could find), TTSX bullets and Varget. Why Varget?-well 1. available, 2 I see it in many other calibers reloading data so I don't need to purchase a ton of different powders now, 3. Temp stability. It can be 90F on opening day and 20F on last day.

Read the Barnes manual, placed the bullets 0.05 off of "jam" as determined by the Hornady tool, and made up some ammo for charge weight testing. Started at min, loaded 5, then increased by 0.5 grain all the way to max (well the last was only a 0.4 change per their recommended max load), 5 rounds at each load weight.

Shot a group at 100 yards for each loading (10 total loadings of 5 each) with 10 min of cool down between loadings. Used LabRadar for chrono.

Why 100 yrds? I'm not an expert shooter. At 200 or more yards my inaccuracies would blow out any differences in the actual ammo.

What I observed:
1. I never found a plateau in velocities. There was a nearly perfect 30 fps increase for each 0.5 additional powder. Smallest delta for fps was 28, largest 44, most were mid-30's. (or do i have the wrong perspective? is a 28 an actual plateau??). FPS's ranged from 2666 to 2964.

2. Only the max load and max-.4 loads gave velocities similar to factory Barnes ammo out of the same gun.

3. I know i'm a newb, but i've looked at every video and webpage i can and i didn't see anything like a classic pressure sign even at max load.

4. Groups got smaller, then larger, then smaller, then larger. But my inaccuracies again come into play. I had 3 loadings in a row with what started as sub 1inch groups, but then 1 pulled shot taking it to a 1.5 inch group.

So big question: where to go from here??

As I see it I could:

1. Work with what I have. Go back to those smaller group sized loads and load some more and maybe even do some smaller variances between loads, say 0.3 grain and verify that there is indeed a node in that area. However-that general area is running 120 FPS slower than factory loads. Would that make a difference in terminal performance of the bullet?

2. Keep pushing up on the powder load until i get pressure signs, or find a definite node, or max out the case.

3. Since i didn't see any pressure signs at max load, just choose that even though it wasn't the smallest group so i can retain the FPS needed for performance, and then see if changing bullet seating would get the accuracy better.

4. Wide open to any other suggestions.

Any good reloading forums? Hate to join more and more internet stuff but if there's one which is considered the cream of the crop, then I 'd potentially join and ask there.

Thanks
cc

A few issues:

• Pressure nodes are largely irrelevant if you don’t have pressure-testing equipment. Forget about them and focus on accuracy. It’s possible to work with Overall Length but the Hornady comparator will let you look at Cartridge Base To Ogive (CBTO) length, which tends to be more consistent.
• Seating depth matters. See details at https://bergerbullets.com/getting-th...in-your-rifle/
• Barnes need speed. Don’t try to outrun factory loads but move it as fast as it will go, then adjust CBTO to tighten groups.
• The shape of groups matters. You adjust that with seating depth. A group with 2+1 means seat them deeper. Three shots evenly spaced in an equilateral triangle means seat out further.
• Varget is a good choice. It works best at top pressures. Look at TAC and CFE 223 for 120-grain bullets and Big Game for 140s and heavier.
• As soon as you get decent groups at 100, push it out to 200 or 300 and continue your tests.

Let me know if you have questions.


Okie John

[Duelist]

That bullet at any of those speeds will absolutely slay deer. They open more reliably at faster speeds, but even your ~2600fps load won’t have dropped below 2000fps before 300 yards, and that’s usually considered a safe threshold for TTSX to open up on impact. Pick the speed and recoil you want, then tune for accuracy.

FWIW, I’m running an LRX in my .270 this year at about 2950 or so. In the .270, that is very much not a max load, but it doesn’t need to be to blow a good hole through a Coues whitetail out farther than I will shoot at one.