AR Rifle 20"

[RONK]

Hi,the recent threads discussing aspects of AR's with 20" barrels coupled with a few YouTube videos,made me curious about this configuration.Where most everyone seems to want an AR with a short and still shorter barrel,the 20" endures.For the members that favor the full size rifle,would you please tell me what you like about it,your application and how you have the rifle configured?I haven't owned an AR in a long time,but this may soon change.Thanks as always.

[Bigghoss]

Well for starters it's the softest shooting for sure. And the looks are just classic. I had to carry a 20" rifle at work for years and hated it. But for plinking at the range they're nice shooters. I may grab one or two at some point. I can't decide between an A2 or an A4 so I might just grab one of each. If I had a plot of land I'd probably keep one in the truck for pest control.

[mmc45414]

I even have a 26", obviously rifle length gas system, and I think the rifle buffer tube makes it even more mellow.https://uploads.tapatalk-cdn.com/20191002/324e38c4d18c524fcc427648b4fd4aa5.jpg

Sent from my SM-G892A using Tapatalk

[Malamute]

I much prefer it for several reasons, they have less perceived muzzle blast, which is a big thing to me, with the fixed stock its easy to spot hits at longer distance with a scope. Shooting a standard carbine stock theres enough wobble in the stock that Id lose the image in the scope firing at stuff 300 or more yards away, with the rifle, its like shooting a 22, no problem seeing the hits. Ive tried the stock that locks into place, its still not as rigid as the fixed rifle stock.

Most of my use is shooting in open country, 300 out to 600-800 yards, and I used them for bunny and jack hunting in Az. The rifle fit me well (Colt SP1 rifle) the first time I tried it on running rabbits I made a first round hit, and that wasnt unusual over time, but the follow-up shots were nice at times.

The A2 were still good, the stock fits well, and the round handguard was an improvement. The flat top is OK, but I made out OK with handle mounted scope mounts, the ARMS mount being the only one I found that didnt shift zero when the gun lived in the truck leaned against the seat and driven down a lot of rough roads. Getting in and out of vehicles a lot and inside a building the carbines would be better, but none of that has much bearing on my use.

For toting around the hills in hand, the carry handle upper fits my hand best, the thumb through the handle, the flat top handle doesnt have a large enough opening. I use the irons mostly for most plinking and carry around in the hills use. The A2 sights are excellent iron sights. White paint or nail polish in the arrows and numbers helps adjust for range and whatever much easier in poorer light, heck any time.

When I see the term "carbine" and get over the initial thought it may be a Winchester carbine, Im meh. Rifle ARs, yes, Im interested.....

Edit: Something I like about rifles, they are simple. No messing with various buffers. Use a rifle buffer. It works. Done. Use a good make of barrel, no worry about port size, blah blah whatever. Standard format rifles just work. Colt makes pretty good ones.

[Doc_Glock]

What would be the 20” iron sighted rifle of choice for a fairly ignorant buyer? I don’t need highest quality, just something decent. The 6920 of this class I guess.

[Bigghoss]

What would be the 20” iron sighted rifle of choice for a fairly ignorant buyer? I don’t need highest quality, just something decent. The 6920 of this class I guess.

As far as I know, there's not a really good A2 clone, but you could easily get an upper and a lower from Aero Precision and put a carry handle on it. Aero Precision makes an A4 clone that runs about $1,000. FN has their collector series A4 clone for about $1600 I think.

[Malamute]

I dont know what other makers are offering, but Colts are the AR15 A4. Other variants have been out for some time, theres a number of Match, Match Target and Match H-Bar guns around that are the same basic thing, but with heavier barrels. If having the front pivot pin require a screwdriver to remove instead of a push pin isnt a problem to you, it gives more of the aforementioned guns a leg up. Many were so made. I had a match H-Bar flat top about 10 years ago that I liked a lot, but had to sell.

[TGS]

What would be the 20” iron sighted rifle of choice for a fairly ignorant buyer? I don’t need highest quality, just something decent. The 6920 of this class I guess.

BCM sells their A4-type upper sans handguard, BCG, CH and carry handle for $439, a complete Brownell's retro musket for just under grand, and a complete PSA 20" A4 is only $519.

One of those is probably the way I'd go, given a complete Aero A4-type is almost $1400.

[Suvorov]

Hi,the recent threads discussing aspects of AR's with 20" barrels coupled with a few YouTube videos,made me curious about this configuration.Where most everyone seems to want an AR with a short and still shorter barrel,the 20" endures.For the members that favor the full size rifle,would you please tell me what you like about it,your application and how you have the rifle configured?I haven't owned an AR in a long time,but this may soon change.Thanks as always.

The 20" A2 will always hold a special place in my collection. First mostly due to nostalgia as the M16A2 was the rifle I mostly used during my military career. In that time I found them to be extremely reliable as well as accurate. My first AR was a Colt Target Sporter which was basically an A2 configuration without a bayonet lug and the ability to drill a hole for a fun switch. It's still one of my favorite ARs to shoot and I have used it for local service rifle matches. The plus sides of the 20" rifle are the longer sight radius which makes shooting with iron sights a little easier, soooper soft recoil, and a little better ballistics at longer ranges. With modern optics the sight radius advantage is negated but if I were to buy a rifle I wanted to shoot with irons - that would be the way to go.


What would be the 20” iron sighted rifle of choice for a fairly ignorant buyer? I don’t need highest quality, just something decent. The 6920 of this class I guess.

If I were going to go out and buy a 20" gun it would most likely be a BCM CHF 20" A4 upper. Lower would be your pick but as other have mentioned in other threads the A5 and even carbine extensions with the right buffer work fine. I'm also a fan of the the longer stroke rifle extension with either the A2 or BCM MOE stock. If I was wanting to spend less then I would probably go with a PSA Premium upper with the FN CHF barrel.

[willie]

I have the A2 that I bought new in 1987. I enjoy shooting it when fooling around on rural property. My lgs has a Colt A4 for under $1100. I'm seriously eyeballing it.

[JRB]

If you want an A2 style fixed carry handle, and you don't mind the ban-era Colt weirdness, you can frequently find a 20in HBAR or similar configuration for $600-700 on Gunbroker. That's a lot of quality for the price, but again, ban-era Colt weirdness bugs some people. If you don't want to change shit on the wepaon and just want to run mags through it and keep it clean, they're a solid choice.

FN made a fantastic ~$900ish version of the FN15 in a 20in A4 configuration, but it was discontinued. You can find them occasionally for pennies on the dollar on gunbroker. For a complete rifle from FN it is a steal because not a lot of folks ever knew they made such a config, so A4 seeking folks aren't really looking for them.
Presently FN only offers an A4 configuration as the collectors edition with the complete KAC rail system and such and it's much more expensive, as previously mentioned.

Bushmaster (yeah, I know) also makes a fixed carry handle A2 clone variant. An Army buddy of mine got one since that was the 'easy button' for a nostalgic A2 clone for him and he's not super into guns and didn't really know any better. Surprisingly, it has been accurate and trouble free for him. Upon inspection it's actually put together OK aside from poor gas key staking and a slightly too-long gas tube, both of which were easy enough to fix. Feature wise it was spot on for an A2 except the 1/9 HBAR profile barrel, the lack of coating on the sling loops, and the plastic buttstock trap door. At $700-750ish street price out the door, you could do worse.

The PSA A2 clones bug me because they use an F marked FSB, which is slightly shorter than the FSB that's correct for a fixed carry handle. This means you need to run the front sight post up much further to zero and for me it kind of wrecks the immersion/authenticity since it's hard to un-see anything on the front sight and actually still use the rifle. Obviously for an A4 or other flattop setup the F marked FSB is the correct thing. Otherwise it's a PSA product and as long as you're willing to fix the little things that were a little off when they put it together, it should be fine.

CMMG makes/made an A1 length fixed stock with A2 features, which is a nice combo if you want something a little shorter than the A2's pole vault but don't want to mess about with adjustable stocks or carbine stocks, or a vintage A1 stock that's $$$ these days because of retro builders.

Personally, I really like a 20in rifle with a 6 or 7 position carbine extension and an H6-ish buffer. But I'm 5ft 9in and in full battle rattle I find the A2 stock to be a pain in the ass, especially getting in and out of confined spaces. The M4 buttstock makes a big difference in that regard. But the needs for a 'working gun' in that regard differ considerably from a field rifle being used as Mr. Malamute described.


I have the A2 that I bought new in 1987. I enjoy shooting it when fooling around on rural property. My lgs has a Colt A4 for under $1100. I'm seriously eyeballing it.

That is a very good price for an LGS. Most rack prices I've seen for a new AR15A4 are in the $1200-1250 range.

[Bigghoss]

I was browsing around and found fixed carry handles uppers from Model 1 sales and Fulton Armory makes uppers and rifles but they're pretty expensive. I have no idea what the quality of either is.

[JRB]

I was browsing around and found fixed carry handles uppers from Model 1 sales and Fulton Armory makes uppers and rifles but they're pretty expensive. I have no idea what the quality of either is.

Fulton has a storied history with long lead times, etc. Lots of info on Arfcom and M4C. Their parts are reputed to be very good, but they're geared more toward NM Service Rifle guns and accuracy builds of that nature.

For a visually milspec accuracy build, I've heard very good things about White Oak Armament's parts and builds, but I don't have direct experience with them.
Having dealt with a few accuracy-focused AR's of that nature, I've found that they tend to be very unforging about ammo selection, and only run well and shoot well with a very specific and narrow range of loads.

If one needs varmit-plinking levels of accuracy, I'd recommend avoiding a milspec appearance entirely and just go with a conventional free floated upper configuration with a good barrel and a good optic.

[Bigghoss]

Fulton has a storied history with long lead times, etc. Lots of info on Arfcom and M4C. Their parts are reputed to be very good, but they're geared more toward NM Service Rifle guns and accuracy builds of that nature.

That's good to know because I used one of their A1 stocks and LPK to build the lower on my favorite AR.

[Doc_Glock]

I have the A2 that I bought new in 1987. I enjoy shooting it when fooling around on rural property. My lgs has a Colt A4 for under $1100. I'm seriously eyeballing it.

I have looked for a Colt A4 available on Davidson’s for a long time and they were always sold out. I would definitely go for that.

Thanks for the Brownells tip above. This also looks to be a good rifle at the price but I don’t really know:

https://www.brownells.com/firearms/rifles/semi-auto/brn-16a1-rifle-5-56mm-20in-black-prod113314.aspx

[Bigghoss]

I doubt it'll happen anytime soon but I would love it if Brownell's made an A2 clone.

[littlejerry]

My first AR was a Colt large hole A2 upper with a 20" govt barrel. It's a great shooter and I still have it today.

[MEH]

Fulton has a storied history with long lead times, etc. Lots of info on Arfcom and M4C. Their parts are reputed to be very good, but they're geared more toward NM Service Rifle guns and accuracy builds of that nature.

For a visually milspec accuracy build, I've heard very good things about White Oak Armament's parts and builds, but I don't have direct experience with them.
Having dealt with a few accuracy-focused AR's of that nature, I've found that they tend to be very unforging about ammo selection, and only run well and shoot well with a very specific and narrow range of loads.

If one needs varmit-plinking levels of accuracy, I'd recommend avoiding a milspec appearance entirely and just go with a conventional free floated upper configuration with a good barrel and a good optic.

Personally I avoid Fulton - just think they are over-hyped and over-priced.

I have a White Oak NM upper that is sweet. I also get all my small parts (LPKs) from White Oak. John and crew are good to go and very responsive.

[OlongJohnson]

For toting around the hills in hand, the carry handle upper fits my hand best, the thumb through the handle, the flat top handle doesnt have a large enough opening. I use the irons mostly for most plinking and carry around in the hills use. The A2 sights are excellent iron sights. White paint or nail polish in the arrows and numbers helps adjust for range and whatever much easier in poorer light, heck any time.

As usual, I like Malamute's perspective. As a guy with fairly large hands, if I'm going to mess with a carry handle, I can see the attraction of a dedicated forging.

Rock River isn't normally at the top of my list for quality ARs, but they seem to be one of the few reasonably reputable sources currently supplying A2 style uppers.

"National Match" rifle:
https://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_ID=156

Complete upper:
https://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_ID=156

You can also get just the forging with sight components, door and FA.

Is any of that worth messing with for a "field rifle" using irons? Which makes the key consideration their sight components. They seem to have some fanciness in their available options. Are they doing it right, or offering lots of different ways that aren't quite awesome?

[Ivantheterrible]

For a visually milspec accuracy build, I've heard very good things about White Oak Armament's parts and builds, but I don't have direct experience with them.
Having dealt with a few accuracy-focused AR's of that nature, I've found that they tend to be very unforging about ammo selection, and only run well and shoot well with a very specific and narrow range of loads.

.

I have shot WOA uppers for years and can frankly say they are of fantastic quality. Their A2 carry handle sights are engineered for competition shooting so are graduated in either 1/2 or 1/4 MOA increments. I currently have one of his A4 NM upper with a pinned sighted carry handle. Outstanding piece of kit for competition shooting but, probably, overkill for what most want from their A2. As for being finicky, NEVER. Of course they've all been my reloads but I've shot over 20k rounds through two of his uppers without a single hiccup - BUT normally cleaned after about every 200-300 rounds.

Not sure if he offers pinned front sight blocks because everything I've seen have been set screwed into flats machined in the barrel. Normally his rifles have free floated barrels.

[Bigghoss]

Rock River isn't normally at the top of my list for quality ARs, but they seem to be one of the few reasonably reputable sources currently supplying A2 style uppers.

*GASP* They have a midlength A2 complete upper...

[OlongJohnson]

So here's the rabbit hole idea this thread has bubbled up in my little terrier brain:


WOA A2 upper with NM pinned rear sight assy
AR15 Performance 20-in 3R barrel & bolt
muzzle device compatible with can system of choice
BCM QRF 12" handguard, relieved as necessary to clear FSB
Zev/Mega forged lower
Geissele SSA-E
BCM Mod2 grip
Magpul MOE rifle stock
20-rd metal Colt mags because they look right
Other stuff is pretty much commodity from quality vendors

Only sticking point is the BCM QRF anti-rotation clip doesn't fit the wider A2 receiver. Would have to get some notches milled to make it the same width as a flat top at that location, or fab an alternate clip.

Reckon this would be fun take-a-walk gun in open spaces out west. Surprises me I can't find any similar builds.

[JRB]

So here's the rabbit hole idea this thread has bubbled up in my little terrier brain:


WOA A2 upper with NM pinned rear sight assy
AR15 Performance 20-in 3R barrel & bolt
muzzle device compatible with can system of choice
BCM QRF 12" handguard, relieved as necessary to clear FSB
Zev/Mega forged lower
Geissele SSA-E
BCM Mod2 grip
Magpul MOE rifle stock
20-rd metal Colt mags because they look right
Other stuff is pretty much commodity from quality vendors

Only sticking point is the BCM QRF anti-rotation clip doesn't fit the wider A2 receiver. Would have to get some notches milled to make it the same width as a flat top at that location, or fab an alternate clip.

Reckon this would be fun take-a-walk gun in open spaces out west. Surprises me I can't find any similar builds.

I dig it! It might be worth some correspondence with WOA to see what lowers best fit their uppers. The ZEV/Mega lowers are great but tolerance creep is tolerance creep, and an outfit in the match rifle business like WOA will know what best fits their stuff.

Also, I'd lean more toward one of their National Match style free floats becuase a free floated quad rail with a fixed carry handle looks pretty incongruous, and there's lots of ways to mount a bipod or light without twelve acres of rail space. Alternatively, going with an Mlok rail gives you all of the same flexibility for bipod/light mounting for less weight and it doesn't look quite as incongruous.

I'd also skip the MOE stock, mostly because I think the MOE fixed stocks look weird. Classic 20 round mags look best with a classic A1 or A2 style stock, IMHO. If it were my rifle to build, I think I'd go with that CMMG A1 length but A2 style stock for a build like this.

[Trigger]

So here's the rabbit hole idea this thread has bubbled up in my little terrier brain:


WOA A2 upper with NM pinned rear sight assy
AR15 Performance 20-in 3R barrel & bolt
muzzle device compatible with can system of choice
BCM QRF 12" handguard, relieved as necessary to clear FSB
Zev/Mega forged lower
Geissele SSA-E
BCM Mod2 grip
Magpul MOE rifle stock
20-rd metal Colt mags because they look right
Other stuff is pretty much commodity from quality vendors

Only sticking point is the BCM QRF anti-rotation clip doesn't fit the wider A2 receiver. Would have to get some notches milled to make it the same width as a flat top at that location, or fab an alternate clip.

Reckon this would be fun take-a-walk gun in open spaces out west. Surprises me I can't find any similar builds.

I have a two rifles with ARP barrels (223 and 22 Predator) and they are both pretty accurate.

[Doc_Glock]

Thanks to willie, I am going to be getting a Colt, this model:

https://www.galleryofguns.com/genie/Default.aspx?item=AR15A4&zipcode=

Hope it works!

[RAM Engineer]

I don't know about their quality, but LUTH has, what I consider to be the best carry-handle upper configuration, the C7:

https://www.luth-ar.com/product/a1-stripped-upper-receiver-w-m4-feed-ramp/

Available with or without M4 feedramps. They also have an A2 upper and a slick-side A1 upper (both without M4 feedramps).

[willie]

Thanks to willie, I am going to be getting a Colt, this model:

https://www.galleryofguns.com/genie/Default.aspx?item=AR15A4&zipcode=

Hope it works!

Great. I'll help you out even more by working it over with my Dremel tool before you take possession.;)

[OlongJohnson]

I dig it!

Also, I'd lean more toward one of their National Match style free floats because a free floated quad rail with a fixed carry handle looks pretty incongruous.

I'd also skip the MOE stock, mostly because I think the MOE fixed stocks look weird. Classic 20 round mags look best with a classic A1 or A2 style stock, IMHO.

I don't wanna turn this place into arfcom, but I found sumdood's photo of his A2 he took in the woods and photochopped the buttstock, grip, handguard and mag onto it. Wanted to see if it looked as right as I thought it would, and it was a lot cheaper than buying all the parts. I like it. My eyes, YMMV. Kinda like a resto-mod muscle car. Old, familiar shape with some modern style and tech nicely integrated. I've never really liked the look of the traditional A1/A2 furniture. The quad rail is almost retro in 2019, but it's also the newest from BCM. There's another thread around here where someone is saying they think the QRF might be the best option due to size, stiffness, ventilation, etc.

[littlejerry]

I'm definitely partial to A2 handguards with my A2 upper. Still looks good with the Vltor stock on it as well.

For whatever reason the Vltor seemed to work brilliantly with A2 irons but never worked right with optics for me.

[willie]

Doc, bless him, is getting a fine rifle. I could find no fault with it. I'm most pleased that one of us is buying the Colt. My fee for the sale was one can of Dr. Pepper.

[JRB]

I don't wanna turn this place into arfcom, but I found sumdood's photo of his A2 he took in the woods and photochopped the buttstock, grip, handguard and mag onto it. Wanted to see if it looked as right as I thought it would, and it was a lot cheaper than buying all the parts. I like it. My eyes, YMMV. Kinda like a resto-mod muscle car. Old, familiar shape with some modern style and tech nicely integrated. I've never really liked the look of the traditional A1/A2 furniture. The quad rail is almost retro in 2019, but it's also the newest from BCM. There's another thread around here where someone is saying they think the QRF might be the best option due to size, stiffness, ventilation, etc.

Just like those restomod muscle cars, each one is a take on what the owner/builder likes and liking different things is part of what makes that whole scene so much fun! The QRF rail is definitely stiff and it would resist heat buildup much better than most modern M-lok etc sorts of rails, so if you're going to run through a half case in an afternoon that'd be a lot more pleasant to work with for sure.
You're right, though, in that a quad rail is basically retro at this point. Crazy how fast this stuff is changing!

Not long after I made that post, I was killing time on BCM's website and found out they offer a 14.5in middy with an A4/M4 style FSB and a few different free floated rails, so now it's likely I'll be buying a matching pair - one for me, and one for my prior-service wife who thinks any AR that doesn't have a traditional FSB 'doesn't look right'. Those plus pin & weld jobs with the appropriate suppressor mounts for a decent can.. heck yeah!

[Bigghoss]

Not long after I made that post, I was killing time on BCM's website and found out they offer a 14.5in middy with an A4/M4 style FSB and a few different free floated rails, so now it's likely I'll be buying a matching pair - one for me, and one for my prior-service wife who thinks any AR that doesn't have a traditional FSB 'doesn't look right'. Those plus pin & weld jobs with the appropriate suppressor mounts for a decent can.. heck yeah!

I just got one of them not long ago and I really like it. Put it on an A1 fixed stock lower and now it's my favorite rifle.

[deputyG23]

If you want an A2 style fixed carry handle, and you don't mind the ban-era Colt weirdness, you can frequently find a 20in HBAR or similar configuration for $600-700 on Gunbroker. That's a lot of quality for the price, but again, ban-era Colt weirdness bugs some people. If you don't want to change shit on the wepaon and just want to run mags through it and keep it clean, they're a solid choice.

FN made a fantastic ~$900ish version of the FN15 in a 20in A4 configuration, but it was discontinued. You can find them occasionally for pennies on the dollar on gunbroker. For a complete rifle from FN it is a steal because not a lot of folks ever knew they made such a config, so A4 seeking folks aren't really looking for them.
Presently FN only offers an A4 configuration as the collectors edition with the complete KAC rail system and such and it's much more expensive, as previously mentioned.

Bushmaster (yeah, I know) also makes a fixed carry handle A2 clone variant. An Army buddy of mine got one since that was the 'easy button' for a nostalgic A2 clone for him and he's not super into guns and didn't really know any better. Surprisingly, it has been accurate and trouble free for him. Upon inspection it's actually put together OK aside from poor gas key staking and a slightly too-long gas tube, both of which were easy enough to fix. Feature wise it was spot on for an A2 except the 1/9 HBAR profile barrel, the lack of coating on the sling loops, and the plastic buttstock trap door. At $700-750ish street price out the door, you could do worse.

The PSA A2 clones bug me because they use an F marked FSB, which is slightly shorter than the FSB that's correct for a fixed carry handle. This means you need to run the front sight post up much further to zero and for me it kind of wrecks the immersion/authenticity since it's hard to un-see anything on the front sight and actually still use the rifle. Obviously for an A4 or other flattop setup the F marked FSB is the correct thing. Otherwise it's a PSA product and as long as you're willing to fix the little things that were a little off when they put it together, it should be fine.

CMMG makes/made an A1 length fixed stock with A2 features, which is a nice combo if you want something a little shorter than the A2's pole vault but don't want to mess about with adjustable stocks or carbine stocks, or a vintage A1 stock that's $$$ these days because of retro builders.

Personally, I really like a 20in rifle with a 6 or 7 position carbine extension and an H6-ish buffer. But I'm 5ft 9in and in full battle rattle I find the A2 stock to be a pain in the ass, especially getting in and out of confined spaces. The M4 buttstock makes a big difference in that regard. But the needs for a 'working gun' in that regard differ considerably from a field rifle being used as Mr. Malamute described.



That is a very good price for an LGS. Most rack prices I've seen for a new AR15A4 are in the $1200-1250 range.

My early '90s Colt Sporter Target was a former nuke plant security rifle that I paid $600 for back in '05. It is more enjoyable to shoot than my M4 -ish Armalite DEF-15. Neither have given me any issues with about 1500 rounds collectively fired.

[RAM Engineer]

https://www.brownells.com/rifle-parts/receiver-parts/receivers/upper-receivers/ar-15-c7-stripped-upper-receiver-prod124803.aspx

Brownells makes a Canadian C7 style upper also.

[OlongJohnson]

The flat top is OK, but I made out OK with handle mounted scope mounts, the ARMS mount being the only one I found that didnt shift zero when the gun lived in the truck leaned against the seat and driven down a lot of rough roads. Getting in and out of vehicles a lot and inside a building the carbines would be better, but none of that has much bearing on my use.

This is interesting.

https://www.brownells.com/optics-mounting/scopes/rifle-scopes/retro-4x-carry-handle-scope-prod124965.aspx

[Suvorov]

This is interesting.

https://www.brownells.com/optics-mounting/scopes/rifle-scopes/retro-4x-carry-handle-scope-prod124965.aspx

That's funny! I still have mine from the 90's, heck I even paid the money to buy the cheek riser for the "Delta" setup. I guess in a world where hipsters ride single speed bikes through the streets of Portland it makes some sense to bring these back....

[Malamute]

This is interesting.

https://www.brownells.com/optics-mounting/scopes/rifle-scopes/retro-4x-carry-handle-scope-prod124965.aspx

I had one of the original Colt scopes like that, it was a good idea at the time, but it had a small field of view, and it also changed zero from my normal use. I never could get it tight enough to stay in place. Using loc-tite in the handle slot to mount surfaces may work, but isnt very removable. They had a bullet drop compensator built into the elevation turret, which was cool, but didnt turn out to be very practical on my gun (Colt SP1).

The only scope mount I found at that time that never changed zero was the ARMS, it was pretty tight going into the carry handle, as in it will remove finish in time, but was reliable for holding zero. It has a hole to use the irons through but it wasnt very quick or easy to do, more like plan B if something happened to the scope. I just adjusted to the higher scope line, but it wasnt as fast to use as a scope that was set up correctly for instant use when you naturally threw the gun up and looked at the target. It made the gun reliable in hitting prairie dogs @ 300 yards consistently with decent ammo. 6-7/10 was common.

http://armsmounts.com/shop/mounts/a-r-m-s-02-m16-scope-mount/

[Nephrology]

I am pretty happy with my RRA Predator Pursuit upper (20" Natl Match bbl). It is easily sub MOA at 100y with factory match ammo.

It's not a very 'tactical' rifle, but it's easily the best paper-punching rifle I own. Would probably be a great varmint rifle if that was a need of mine.



I'd also skip the MOE stock, mostly because I think the MOE fixed stocks look weird. Classic 20 round mags look best with a classic A1 or A2 style stock, IMHO. If it were my rifle to build, I think I'd go with that CMMG A1 length but A2 style stock for a build like this.

I had both, the fixed MOE stock was much more comfortable and sturdy for the dollar. Most of the A2 stocks I looked at weren't very well made. Best I could find was the Fulton Armory model at ~$130 which included a metal buttplate. I returned it and paid ~$60 for the MOE fixed stock, which had better cheekweld and more storage too. Agreed it doesn't look quite as classic but whatever.

https://i.imgur.com/Ey9R7Ht.jpg

[Doc_Glock]

Here is the new 20” above the old reliable short lightweight.

43570

7lbs 10oz. The smaller rifle including sling, light and optic is 6lb 10oz.

I have to imagine the 20” to be an incredibly sweet shooter.

[Doc_Glock]

I zeroed the 20” today at the indoor range so it is a rough zero. I followed the Colt instructions for zeroing the rifle at 25M using the Z setting on the elevation dial.

I had to dial the front sight down significantly to get centered, maybe 3”. I hope the “Z” setting accounts for the sight offset at 25 yards. Will just have to see once I can stretch it out.

Supposedly this process with the carry handle sight gives a 25/300 zero. I usually use a 100 yard zero on other rifles but thought I would follow Colt’s recommendation here.

I am absolutely amazed that with my eyes, and the crappy indoor lighting and the dark front over the dark bull, I was able to still do 3/4” groups at 25. I am a 4MOA shooter with this ammo using irons and unmagnified sights outside in good lighting, so I guess that is appropriate. Still, the group is smaller than the front sight post by a lot. The old peep sight system is pretty amazing to this pistol shooter.

I then did some close range dots at 5 to learn offset and it went just fine. Amazingly easy firearm to shoot.

Zero functional issues. The trigger is kinda bad, but meh. Will break in.

[OlongJohnson]

Trying to make sure I know what someone should know about A1/A2 receiver extensions / buffer tubes for rifles.

I've seen comments elsewhere that mil-spec for rifle receiver extensions is 7075 with rolled threads.

Obviously, 7075 is going to be stronger (~2x) than 6061, so I'd rule out 6061.

Not everyone understands this, but I'm enough of a fastener geek to know that rolled threads versus cut threads is actually a yuuuge deal. If TDP specifies rolled threads, then presumably a Colt tube has them. And the aftermarket being what it is, it's extremely unlikely any other manufacturer is bothering. Which would mean no other part really comes close.

It's been years since I looked at rob_s' list; I don't remember it dealing with rifle stuff, but I was focused on carbines at the time.

TLDR: If I want the best rifle-style receiver extension, I just buy a Colt tube and roll on, right?

[JRB]

Trying to make sure I know what someone should know about A1/A2 receiver extensions / buffer tubes for rifles.

I've seen comments elsewhere that mil-spec for rifle receiver extensions is 7075 with rolled threads.

Obviously, 7075 is going to be stronger (~2x) than 6061, so I'd rule out 6061.

Not everyone understands this, but I'm enough of a fastener geek to know that rolled threads versus cut threads is actually a yuuuge deal. If TDP specifies rolled threads, then presumably a Colt tube has them. And the aftermarket being what it is, it's extremely unlikely any other manufacturer is bothering. Which would mean no other part really comes close.

It's been years since I looked at rob_s' list; I don't remember it dealing with rifle stuff, but I was focused on carbines at the time.

TLDR: If I want the best rifle-style receiver extension, I just buy a Colt tube and roll on, right?

After going through the same dilemma, and being disappointed in discovering that the Colt A2 stock kit comes with a commercial buttplate and therefor deviates from the TDP, I opted for an AR-Stoner 'extreme duty' 7075 T6 receiver extension.
I found USGI A2 stock and A2 buttplate for sale on fleabay to round out the ensemble.
I was looking to duplicate a 'rack grade' M16A2 with that build, so the worn A2 stock and buttplate were exactly what I wanted.

But I did not scrutinize the threads on the AR-Stoner to see if they were rolled or cut, I simply wanted to avoid 6061.

Brownell's also offers a 7075 rifle length extension for a surprisingly cheap price ($27) but no word on the threads there, either.

[OlongJohnson]

I have the Colt and Brownells parts in my cart. May just order the Brownells extension and return it if the threads are cut.

[Bigghoss]

Trying to make sure I know what someone should know about A1/A2 receiver extensions / buffer tubes for rifles.

I've seen comments elsewhere that mil-spec for rifle receiver extensions is 7075 with rolled threads.

Obviously, 7075 is going to be stronger (~2x) than 6061, so I'd rule out 6061.

Not everyone understands this, but I'm enough of a fastener geek to know that rolled threads versus cut threads is actually a yuuuge deal. If TDP specifies rolled threads, then presumably a Colt tube has them. And the aftermarket being what it is, it's extremely unlikely any other manufacturer is bothering. Which would mean no other part really comes close.

It's been years since I looked at rob_s' list; I don't remember it dealing with rifle stuff, but I was focused on carbines at the time.

TLDR: If I want the best rifle-style receiver extension, I just buy a Colt tube and roll on, right?

I wish I had heard this before I put together my fixed-stock middy, I've never even heard of rolled threads. I guess it's not a big deal to swap it out once a proper one is found. Does anyone know what Fulton Armory uses for their rifle receiver extensions?

[HeavyDuty]

Oh, God - receiver extension thread cork sniffing...

(Ducks)

[OlongJohnson]

No, this is about screwing to win (https://www.amazon.com/Nuts-Bolts-Fasteners-Plumbing-Handbook/dp/B001OXCTSI/).

[OlongJohnson]

It's been years since I looked at rob_s' list; I don't remember it dealing with rifle stuff, but I was focused on carbines at the time.

Waiting for lunch to heat up, I dug through my desktop machine and found all the "chart" info I saved back in the day. (I was late to the game and only have the discussion of criteria post-2012, plus a screencap I found somewhere of an uknown version of what I assume was the actual chart.) It is only M4 specific, so no breakdown of rifle vs. carbine. For buffer tubes, it discusses only diameter. Nothing about materials or manufacturing processes.

[Old Man Winter]

Deleted

[awp_101]

https://i.imgur.com/Ey9R7Ht.jpg

I keep coming back to look at this. I can't think of a single practical reason to build an 18" or 20" when my 16" is perfectly fine for any reasonable need I may have but dang if this one doesn't have the hamsters in my brain running in overdrive.

And now I remember I have a side charging upper receiver I'd put back for a project that never happened and I've been meaning to strip the Poverty Pony lower on my "good" carbine and put the parts in the spare Aero stripped lower so my "good" carbine becomes a "better" carbine. Sonofabitch this is about to get real...

[RONK]

Thanks!Any suggestion about buying/building an AR 20" DMR,stainless or chrome lined(SAM-R?),trigger,etc?Thanks again.

[Nephrology]

I keep coming back to look at this. I can't think of a single practical reason to build an 18" or 20" when my 16" is perfectly fine for any reasonable need I may have but dang if this one doesn't have the hamsters in my brain running in overdrive.

And now I remember I have a side charging upper receiver I'd put back for a project that never happened and I've been meaning to strip the Poverty Pony lower on my "good" carbine and put the parts in the spare Aero stripped lower so my "good" carbine becomes a "better" carbine. Sonofabitch this is about to get real...

Big, heavy, no recoil, stupid accurate. Why don't you own one already? :)

[awp_101]

Big, heavy, no recoil, stupid accurate. Why don't you own one already? :)
Ummmm, reasons? And probably not very good reasons at that.

How long is that handguard? 12"? 13"?

[Nephrology]

Ummmm, reasons? And probably not very good reasons at that.

How long is that handguard? 12"? 13"?

12" I believe.

[awp_101]

Thanks!

[Bigghoss]

This will be of interest to most in this thread. Used Colt Sporter Target upper with BCG and CH for $400 shipped. I was SOOO close to ordering one but it would not be financially smart for me at the moment. If they still have any in stock next payday I'll probably get one.

A complete Aero A2 lower is $250 plus whatever shipping and transfer costs are. $700 for a pretty good A2 style rifle.

https://www.armsunlimited.com/Colt-AR15-SP1-Complete-Upper-Receiver-Assembly-p/cura-sp1.htm?CartID=1

[Outlier]

This will be of interest to most in this thread. Used Colt Sporter Target upper with BCG and CH for $400 shipped. I was SOOO close to ordering one but it would not be financially smart for me at the moment. If they still have any in stock next payday I'll probably get one.

https://www.armsunlimited.com/Colt-AR15-SP1-Complete-Upper-Receiver-Assembly-p/cura-sp1.htm?CartID=1

Out of stock.

[Bigghoss]

Out of stock.

I figured they wouldn't last long.

[Bigghoss]

Capco surplus M16A2 uppers.

https://www.doaarms.com/Capco-M16A2-20-Upper-1-7-MP-5-56-Chrome-Lined-p/cm16a2.htm

[TCinVA]

I snagged one of the NOS FN M16A4 uppers they have at DOA from someone else for around $400...which I thought was a pretty good package price for a genuine FN 20" setup. I have an old Bushmaster A2 lower that I am mating it to for giggles. I'll probably replace the MATech rear sight with a carry handle.

Of course, I guess what I'm supposed to do is put an ACOG on it.

[Bigghoss]

Of course, I guess what I'm supposed to do is put an ACOG on it.

I want to get an A4 clone with an ACOG too. Almost as much as I want an A2 clone.

[fatdog]

FWIW,
I have been planing an A2 build for quite some time and snagged one of these DOA Capco uppers. It arrived today, excellent condition, appears to have very little use and the finish is intact, a few small scratches. Thanks for posting that!

Sorta feels sad that something I bought new back in '87 or '88 (a large pin Colt A2) and shot in club level 100 yard NRA HiPower matches for a couple of years is now a "retro AR". But glad to have one again.

[Brian T]

I'd like to build the US Army's version of the M16A2, which I believe Colt kinda gave the model number 715.

Upper:

C7 Upper
1/7" 20" A1 profile barrel
A2 FH
A2 forend

Lower:

A2 Lower
A1/A2 pistol grip (Army apparently didn't care)
Safe/Semi/FA lower (no I would do that)
"CS1" stock (A1 length, A2 material and construction)

[ECVMatt]

I will admit that in my heart I am an A2 kind of guy. I have a few M4ish rifles and like them, but when I am out in the desert or other open areas the A2 is my friend. I don't have to worry about velocity being too low, carbine gas issues, or heavy buffers. Here is a couple of pics of my first and favorite AR from the middle 90's: an Eagle Arms ER-15. They were about as close as you could get to the real thing back in the 1990's.

46184

46185

This has been a great rifle! It is very accurate, shoots very soft, and has been trouble free for about 25 years. I would recommend that everyone give the 20" a try, they are a great package.

[Willard]

ECVMatt who made that mag pouch? Thanks.

[ECVMatt]

It was a very early version of this one:

https://www.simplyrugged.com/ecommerce/223-Pouch-Leather-Ammo-Pouch.cfm?item_id=179&parent=671

I see they have updated the design a bit.

Hope this helps,

Matt

[MistWolf]

I will admit that in my heart I am an A2 kind of guy...I don't have to worry about...heavy buffers...
Of course not. Of all the issue buffers, the rifle buffer is the heaviest.

[Doc_Glock]

In case anyone needs facilitating. Back in stock $1075:

https://www.gandrtactical.com/Colt-AR15A4-20-Rifle_p_241.html

[jc000]

I really need an A1 :(

[Bigghoss]

In case anyone needs facilitating. Back in stock $1075:

https://www.gandrtactical.com/Colt-AR15A4-20-Rifle_p_241.html

Armsunlimited has them for $76 less. Not sure what the shipping costs are between the two.

https://www.armsunlimited.com/Colt-AR15-A4-Semi-Auto-20-inch-Barrel-Rifle-p/ar15a4.htm

[MistWolf]

Armsunlimited has them for $76 less. Not sure what the shipping costs are between the two.

https://www.armsunlimited.com/Colt-AR15-A4-Semi-Auto-20-inch-Barrel-Rifle-p/ar15a4.htm

I picked a bad month to pay the rent

[Suvorov]

Summoning the dark powers of necromancy I hereby raise this thread!

Nine Hole Review just did this video on my favorite Musket!


https://www.youtube.com/watch?v=sqOiTXmi1QU&t=139s

This video just makes me want to head out to the KD range and spend some quality time with my A2.

[BWT]

Summoning the dark powers of necromancy I hereby raise this thread!

Nine Hole Review just did this video on my favorite Musket!


https://www.youtube.com/watch?v=sqOiTXmi1QU&t=139s

This video just makes me want to head out to the KD range and spend some quality time with my A2.

Colt AR15-A4’s are very reasonably priced for what they are.

https://www.kygunco.com/product/colt-ar15a4-ar-15-a4-5.56-223-20-black-301-a2-fixed-stock?utm_source=gun.deals&utm_medium=Product%20Feed&avad=211021_f2aa62659

Not that I was shopping.

[Suvorov]

Colt AR15-A4’s are very reasonably priced for what they are.

https://www.kygunco.com/product/colt-ar15a4-ar-15-a4-5.56-223-20-black-301-a2-fixed-stock?utm_source=gun.deals&utm_medium=Product%20Feed&avad=211021_f2aa62659

Not that I was shopping.

Nor was I but that is one sexy rifle with an even more sexy roll mark!

Are Colts these days coming without all the stupid concessions that the Sporters of the 1990s came with (receiver blocks, large pin FCG, semi-auto BCG?).

Not that I need one but at that price……

So so pretty…..

[oregon45]

I picked up one of those Colt AR-15A4's earlier this year; with the exception of the ambidextrous safety, A2 butt stock and A4 laser markings the lower appears identical to the Colt CR6920's I've seen.

[Joe in PNG]

I pieced together a 20" from a KE poly lower & Colt MOE upper:

93680

[Rick R]

Several years ago I attended a carbine/rifle class at PFT here in WV, between squads a few of the aficionado types were discussing what ammo “worked as good out of their ( insert preferred barrel length 16.5”, 14.5”, 12.5”, etc) as out of a 20”.
That started an idea that smoldered a couple years until I built a 20” rifle with a light weight slimline Midwest rail, 20” FN M16 barrel, ALG trigger, A2 FH and Magpul fixed rifle stock. Kind of a bog simple Recce Musket.
Because any ammo out of a 20” barrel is as good as ammo out of a 20” barrel.

There were a few accuracy issues that I’ve finally sorted out (FN and Vortex’s CS are both quite commendable), but it has been 100% reliable plus everyone who shoots it immediately comments on how smooth the recoil cycle is and how flat it shoots.

My building clearing, jumping out of a squad car days are over, IMHO 20” guns are just more gentlemanly to shoot.

[Suvorov]

OK.

Since everyone else is now (or has) show theirs- This is my rife, there are many others like it but this one is mine.

It is my first AR purchased back in 1994. A pre ban Colt Sporter Target. It’s travelled along my side, lived it the BOQ with me, and has been the rifle I judge all others by. Because of Kalifornia it now sits on a Stag lower, but will soon be mated back to its funky Colt Lower. A couple years ago I replaced the front sight base so I could have a bayonet lug on it. I actually told my wife I want to be buried with it.

CAN NOT WAIT TO TAKE THIS TO THE FORT CARSON RANGE THIS FALL!!! (Though without the bayonet) GyroF-16 and Ichiban

93681

[GyroF-16]

OK.

Since everyone else is now (or has) show theirs- This is my rife, there are many others like it but this one is mine.

It is my first AR purchased back in 1994. A pre ban Colt Sporter Target. It’s travelled along my side, lived it the BOQ with me, and has been the rifle I judge all others by. Because of Kalifornia it now sits on a Stag lower, but will soon be mated back to its funky Colt Lower. A couple years ago I replaced the front sight base so I could have a bayonet lug on it. I actually told my wife I want to be buried with it.

CAN NOT WAIT TO TAKE THIS TO THE FORT CARSON RANGE THIS FALL!!! (Though without the bayonet) GyroF-16 and Ichiban

93681

I’m in!

[Malamute]

Nor was I but that is one sexy rifle with an even more sexy roll mark!

Are Colts these days coming without all the stupid concessions that the Sporters of the 1990s came with (receiver blocks, large pin FCG, semi-auto BCG?).

Not that I need one but at that price……

So so pretty…..

Yes, they stopped all that nonsense many years ago. Standard parts for the most part.

[Suvorov]

My building clearing, jumping out of a squad car days are over, IMHO 20” guns are just more gentlemanly to shoot.

Ironically - while all the guys on foot had M4s we had an M16A2 in the tank. At least it fit in the rack nice.

[Lex Luthier]

I pieced together a 20" from a KE poly lower & Colt MOE upper:

93680

I am very curious about the balance of the KE lower equipped one. Is it at all muzzle-heavy?

[breakingtime91]

I first learned to shoot in the marine corps with the m16a2 and then in infantry school shoot a m16a4 with the brand new peq 15 back then. Man, what a rifle but it was long and heavy. When I got to my unit I was issued a m4a1 and was in heaven. I still have a very soft spot in my heart for m16s... I even wished at certain points I had an A4 on deployment for the extra barrel length and velocity.

[Joe in PNG]

I am very curious about the balance of the KE lower equipped one. Is it at all muzzle-heavy?

It does tend to weigh towards the muzzle side. Of course, I didn't go full WWSD on the upper, so it is to be expected.

[03RN]

My surplused FN upper.
93703
Reminds me of the good old days and I'd be pretty content if it was my only rifle except for hunting.93704

https://youtu.be/Qu_ENIGH_GI

[Molon]

TLDR: If I want the best rifle-style receiver extension, I just buy a Colt tube and roll on, right?

Colt produces both 6061 extruded and 7075 forged rifle receiver extensions.

https://www.ar15.com/media/mediaFiles/28568/colt_rifle_receiver_extensions_001-2513981.jpg

....

[Molon]

I usually use a 100 yard zero on other rifles


.

If you want a 100 yard zero, you can use my RIBZ zero.



RIBZ

Revised Improved Battlesight Zero

The standard A2 rear sights on an AR-15/M16A2 were designed with elevation settings for 300 to 800 meters. The Santose Improved Battlesight Zero allows for an elevation setting of 50 yards/200 meters for one of the most all-around useful trajectories obtainable with the 5.56mm/223 Remington cartridge when fired from an AR-15.

Neither of the above sighting schemes allow for an elevation setting giving you point of aim equals point of impact at 100 yards. Since 100 yard shooting ranges are some of the most commonly found ranges in the United States and some agencies are promoting the use of a 100 yard zero, it would be useful to have such a setting on our AR-15s. This can be achieved quite easily with nothing more than a 1/16” allen wrench. It’s really just a matter of taking the Improved Battlesight Zero one step further.

There is a witness hole on the A2 rear sight base that gives you access to the index screw that you will need to loosen with the 1/16” allen wrench to make the necessary alteration to the elevation drum. The witness hole lines up with the index screw only when the elevation drum is set to 8/3. Set your elevation drum on the 8/3 setting and turn the screw counter-clockwise 3 to 4 complete turns. You don’t want to remove the screw. You want to loosen it enough to allow the elevation index wheel (the top part of the elevation drum with the numbers on it) and the elevation knob (the bottom part of the elevation drum) to separate and be able to move independently of each other.


https://www.ar15.com/media/mediaFiles/28568/index_screw_access_01-1301950.jpg

https://www.ar15.com/media/mediaFiles/28568/index_screw_access_02-1301951.jpg

https://www.ar15.com/media/mediaFiles/28568/allen_wrench_01-1301956.jpg

https://www.ar15.com/media/mediaFiles/28568/allen_wrench_00-1301955.jpg

https://www.ar15.com/media/mediaFiles/28568/index_screw_02-1301960.jpg



Once you have loosened the index screw, use one hand to hold the allen wrench in place on the screw and with your other hand turn the elevation knob (the bottom part of the elevation drum) 4 clicks clockwise.* You should see the rear sight base moving up while you do this. The elevation index wheel should not move while you are doing this. (We really only need to turn the elevation knob 3 clicks clockwise, but by turning it 4 clicks we get a “buffer zone” that keeps the rear sight base from coming into contact with the lower receiver when the sight is moved to the lowest used setting. This gives you a more consistently repeatable sight setting.)



https://www.ar15.com/media/mediaFiles/28568/colt_rear_sight_diagram_03-1301972.jpg



Now that you have moved the elevation knob 4 clicks clockwise, taking care to make sure the elevation index wheel has not moved, firmly tighten the index screw. Starting with the elevation drum at the 8/3 setting, you should easily be able to turn the drum counter-clockwise 3 clicks and see the rear sight base moving down. (You should be able to turn the elevation drum one more click counter-clockwise for our “buffer zone.”) You are now ready to head to the shooting range.

As I mentioned earlier, this sighting scheme is really just taking the Improved Battlesight Zero one step further. Starting with the elevation drum at the 8/3 setting, turn the elevation drum counter-clockwise 3 clicks (8/3, -3). This is your 100 yard point of aim equals point of impact setting. From a distance of 100 yards, zero the rifle with the rear sight at this setting (using the small sight aperture). Do not change this rear sight elevation setting while zeroing. Use the front sight post only to make changes in elevation while zeroing.

The beauty of the RIBZ sighting scheme is that once you have zeroed the rifle with this method, you will have your 100 yard zero setting and the other settings of the elevation drum remain roughly intact depending upon a number of variables. If you want to use the Improved Battlesight Zero, simply set the elevation drum to 8/3, -2 and you're good to go. To use the standard military 300 meter setting, just set the elevation drum to 8/3. You can also start the zeroing process by obtaining the Santose Improved Battlesight Zero at a distance of 50 yards with the rear sight on the 8/3, -2 setting. Obviously, slight variations will be encountered depending on the ammunition used and the actual amount of movement with each click of the various sights. The results will certainly be close enough “for government work.”

When using this sighting method, you may find that once you have set your 100 yard zero, the top of the base of the front sight post is now slightly above the top of the well in the front sight base. If this happens, the “0.040” taller” front sight post from Bushmaster provides a quick and inexpensive fix.


https://www.ar15.com/media/mediaFiles/28568/front_sight_posts2-1301973.jpg

100 yard zero (8/3, -3)

https://www.ar15.com/media/mediaFiles/28568/100_yard_setting_01-1301970.jpg

https://www.ar15.com/media/mediaFiles/28568/100_yard_setting_02-1301971.jpg

https://www.ar15.com/media/mediaFiles/28568/100_yard_zero_01-1301976.jpg



Improved Battlesight Zero (8/3, -2)

https://www.ar15.com/media/mediaFiles/28568/IBZ_setting_01-1301980.jpg

https://www.ar15.com/media/mediaFiles/28568/IBZ_setting_02-1301981.jpg

https://www.ar15.com/media/mediaFiles/28568/improved_battle_sight_zero_01-1301982.jpg



Standard 300 meter zero (8/3)

https://www.ar15.com/media/mediaFiles/28568/300_meter_zero_01-1301989.jpg


* All click references should be doubled when using detachable carry handle sights.


IBZ (6/3, -4)



https://www.ar15.com/media/mediaFiles/28568/carry_handle_02-1301992.jpg


While the Revised Improved Battlesight Zero is certainly not perfect, here is an example of how well it does work at the distances typically encountered at the public KD ranges in my state. I zeroed my 20” Colt with A2 sights at 100 yards as described in this thread. Here is a pic of a 10-shot group from 100 yards.


100 yards, (8/3, -3)


https://www.ar15.com/media/mediaFiles/28568/example_100_yards_01-1302002.jpg

https://www.ar15.com/media/mediaFiles/28568/Colt_A2_HBAR_03_framed_02-1301999.jpg

Next, I packed up my gear and headed to the 50 yard line. By simply coming up one click on the elevation wheel (8/3, -2), I was in the 10-ring at 50 yards.

50 yards, (8/3, -2)

https://www.ar15.com/media/mediaFiles/28568/example_50_yards_01-1302001.jpg

Lastly, I moved down to the 25 yard line. With this sighting scheme, setting the elevation wheel to (8/3, +3) gives me the necessary elevation for 25 yards. (Again, due to the course adjustment of the AR-15 sights and manufacturing tolerances none of these settings are perfect.) In fact, if you don't have access to a 100 yard range or you just want to “get on paper” before heading to the 100 yard range to refine the zero, you can zero at 25 yards using this setting.

25 yards, (8/3, +3)

https://www.ar15.com/media/mediaFiles/28568/example_25_yards_01-1302000.jpg


……


AR-15 Zeros and Trajectories


The 100 yard zero with a .223/5.56mm AR-15 carbine is a unique trajectory in that the bullet just “kisses” the line of sight at 100 yards and rides along it for approximately 10 yards before dropping back down below the line of sight. (Technically, the bullet does travel above the line of sight, but by only 0.010”; a fraction of the diameter of the bullet itself.)



https://www.ar15.com/media/mediaFiles/28568/100_yard_zero_data_01-1301858.jpg



For all other zeroing schemes, there are going to be two points were the bullet crosses the line of sight; the near-zero and the far-zero. For the near-zero, the bullet will cross the line of sight while traveling upward from the muzzle toward the apogee or “maximum ordinate,” its highest point of travel. For the far-zero, the bullet will cross the line of sight while traveling downward from the maximum ordinate.

Now, when assigning a name to a particular zeroing scheme, it would be helpful if that name gave descriptive information about that particular zero; that is, the name should give us information about the trajectory and how it is unique and differs from other trajectories.

As a point of reference, the Santose Improved Battlesight Zero is often referred to as a 50/200 yard zero, however this is incorrect. It is actually a 50 yard/200 meter zeroing scheme; and this is only with a very few particular combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore. As an example, a 20” barreled AR-15 A2 firing 62 grain M855 will not match the 50 yard/200 meter IBZ. Neither will a 16" barreled RECCE firing 77 grain MK262, nor a 14.5” barreled M4 carbine firing the 70 grain 5.56mm Optimized "Brown Tip" load. The same concept applies when people refer to a 50/225 yard zero. Only a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore will match that description.

What this is all leading up to is this; except for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, a 50 yard zero is a different zero than a 200 yard zero. For a 200 yard zero, we know that this trajectory will produce a far-zero in which the bullet will cross the line of sight at 200 yards in its downward travel from the maximum ordinate. (It is physically impossible to produce a 200 yard near-zero with any of the commonly available loads and barrels lengths used in .223/5.56mm AR-15s.) Other than for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, the near-zero of the 200 yard zero will not be at 50 yards.

Conversely, a 50 yard zero tells us that this trajectory will have a near-zero in which the bullet crosses the line of sight at a distance of 50 yards in its upward travel to the maximum ordinate. For those who think that a zeroing scheme must be named after its far-zero, it is physically impossible to produce a far-zero of 50 yards with any of the commonly used loads and barrel lengths in .223/5.56mm AR-15s. The 50 yard zero can only be the near-zero.

Here are a couple of illustrations to aid in understanding some of the concepts described above. Lets start with the 100 yard zero as a reference point. As described above, with a 100 yard zero, the bullet’s trajectory just “kisses” the line of sight at 100 yards. Now, let’s increase the elevation setting of the sights/scope. As this is done, the near-zero can only move closer and closer to the muzzle. Concomitantly, the far-zero moves farther and farther away from the muzzle.



https://www.ar15.com/media/mediaFiles/28568/positive_elevation-1301877.gif



For the next illustration, we’ll start with the 100 yard zero again, only this time let’s decrease the elevation setting of the sights/scope. As this is done, the bullet’s trajectory can only fall away from the line of sight. The bullet will never cross the line of sight again; no zero at all.



https://www.ar15.com/media/mediaFiles/28568/negative_elevation-1301880.gif

Other than for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, the far-zero of the 50 yard zero will not be at 200 yards; and for all practical purposes it matters not one bit. Whether the bullet crosses the line of sight for the second time (far-zero) at 189 yards, 200 yards, 215 yards or 225 yards will not make the slightest bit of difference in the practical application of the AR-15 as a defensive weapon. In each case we will be holding the same POA (beyond CQB distances) and know that we will be hitting within approximately 2 inches above or below that POA out to 200 yards (or farther depending upon barrel length and load.) You should have an idea what your actual far-zero is when using a 50 yard zero and confirm such at distance when possible, but again it’s most likely not going to be a 200 yard far-zero and again it does not need to be.

Choose your zeroing scheme based on the pertinent facts; not nonsense about “shooting through a cone.” When shooting at human targets, in the grand scheme of things there isn’t going to be any practical difference between a point of impact that has a negative deviation from the point of aim, (e.g. the bullet strikes 1.5” below the point of aim) and a point of impact that has an equal positive deviation from the point of aim (e.g. the bullet strikes 1.5” above the point of aim.) In other words, the absolute value of the point of impact from the point of aim (how far the point of impact deviates from the point of aim, regardless of whether it is a positive or negative deviation) is what we need to be concerned about. Therefore, one of the main points to consider when choosing a battle-sight-zero is this: What zeroing scheme produces the smallest absolute values for the deviations of the points of impact from the point of aim, over the distance that we reasonably expect to engage a human target in our intended usage?

The chart below illustrates the above concept. The chart compares the absolute values of the deviations of the points of impact from the point of aim (0.0 inches on the graph being the point of aim/line of sight) for a 50-yard-zero and a 100-yard-zero, using Hornady 5.56 TAP T2 ammunition.


https://www.ar15.com/media/mediaFiles/28568/absolute_value_of_poi_from_poa_02-1301881.jpg


As you can see in the graph above, from the muzzle (0 yards) to approximately 62 yards, the 50-yard-zero has a slight advantage over the 100-yard-zero. Between the distances of 62 yards and 165 yards, the 100-yard-zero has the advantage. From the distance of 165 yards out to the 250 yards shown in the graph, the 50-yard-zero has a distinct advantage over the 100-yard-zero. Choose your zeroing scheme based on the pertinent facts.

Some reference material. Except where noted, all barrel lengths are 20 inches


https://www.ar15.com/media/mediaFiles/28568/trajectory_with_sight_illustration_from_-1301869.jpg
Courtesy of zrxc77

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M855 25 yard zero

https://www.ar15.com/media/mediaFiles/28568/M855_25_yard_zero_from_20_inch_barrel_-1301862.jpg



M855 25 meter zero

https://www.ar15.com/media/mediaFiles/28568/M855_25_meter_zero_from_20_inch_barrel_0-1301861.jpg



M855 36 yard vs 100 yard zero

https://www.ar15.com/media/mediaFiles/28568/M855_36_vs_100_yard_zeros_20_inch_barrel-1301863.jpg



M855

https://www.ar15.com/media/mediaFiles/28568/25_meter_zero_versus_300_meter_zero_02-1301913.jpg

M855 and M193 25 meter zero

https://www.ar15.com/media/mediaFiles/28568/m855_and_m193_25_meter_zero_from_20_inch-1301865.jpg

M855 and M193 50 yard zero from 16” barrel

https://www.ar15.com/media/mediaFiles/28568/M855_vs_M193_16_inch_barrel-1301924.jpg



M193 25 meter, 50 yard and 100 yard zeros from 16" barrel

https://www.ar15.com/media/mediaFiles/28568/m193_from_16_inch_barrel_25_50_and_100_z-1301860.jpg

100 yard zero

https://www.ar15.com/media/mediaFiles/28568/m855_and_m193_100_yard_zero_from_20_inch-1301867.jpg

25 meter vs 50 yard zero, M855 from 16” barrel

https://www.ar15.com/media/mediaFiles/28568/50_yard_versus_25_meter_zero_with_M855_f-1301857.jpg

25 meter vs 50 meter zero , M193 from 16" barrel

https://www.ar15.com/media/mediaFiles/28568/50_yard_versus_25_meter_zero_with_M855_f-1301857.jpg

M855 300 meter zero

https://www.ar15.com/media/mediaFiles/28568/300_meter_zero_02-1301859.jpg



M855 200 meter zero 16" and 20" barrels

https://www.ar15.com/media/mediaFiles/28568/m855_200_meter_zero_20_and_16__barrels_0-2225395.jpg



M855 200 meter vs 300 meter zeros

https://www.ar15.com/media/mediaFiles/28568/M855_200_meter_vs_300_meter_zero_with_20-1301864.jpg



M855 36 yard vs 50 yard zeros

https://www.ar15.com/media/mediaFiles/28568/36_yard_vs_50_yard_zero_from_20_inch_bar-1301856.jpg




......

[Malamute]

Colt produces both 6061 extruded and 7075 forged rifle receiver extensions.

https://www.ar15.com/media/mediaFiles/28568/colt_rifle_receiver_extensions_001-2513981.jpg

....


How does one tell the difference to order the one they want? Or where can you order the forged one and be sure of which one youre getting?


And thanks for the zero info with the set screw for closer zeroing. Id seen it several years ago on M4C I believe, but the refresher was good. I use irons for most of my AR shooting (little as it is any more), out to 6-800 yards. Having the correct 100 yd zero is nice. I used to hunt small game with mine long ago in Az. Shooting running rabbits was hugely fun. Having a good closer zero was nice to have of course.

[Molon]

How does one tell the difference to order the one they want? Or where can you order the forged one and be sure of which one youre getting?

For the Colt rifle receiver extensions, the forged tube will cost significantly more money than the extruded tube. If the vendor provides a detailed picture, you can distinguish the two by the threads. If the picture isn't detailed enough, the Colt forged tube has a grey exterior finish, while the Colt extruded tube has a black finish.

...

[HeavyDuty]

If you want a 100 yard zero, you can use my RIBZ zero…

I’ve been using your method for years - thank you for posting this again, I lost my working copy a few years ago. Is there any chance you have this in PDF format for ease of retaining?

[Suvorov]

I’ve been using your method for years - thank you for posting this again, I lost my working copy a few years ago. Is there any chance you have this in PDF format for ease of retaining?

Agreed!

[Doc_Glock]

If you want a 100 yard zero, you can use my RIBZ zero.......

Thank you for that detailed article!

[JRB]

As a follow-up to that awesome RIBZ article by Molon -

Sarco Inc has the +0.040" front sight posts for a pittance:

https://www.sarcoinc.com/ar15-m16-front-sight-post-040/

[Suvorov]

As a follow-up to that awesome RIBZ article by Molon -

Sarco Inc has the +0.040" front sight posts for a pittance:

https://www.sarcoinc.com/ar15-m16-front-sight-post-040/

Thanks!

Been looking for these!