Gentlemen,
How accurate are our service Carbines? Use a Colt 6920 or an LMT or whatever 16" carbine you want with the standard trigger. Use 100 yards as the distance and ammo like XM193…
What should we be able to expect from these guns 4-5 MOA?
Thanks,
Jack
I saw the spec in one of the Army manuals, but I don’t remember which one.
It’s in there though under “general specifications”.
Same here, IIRC its 4MOA. It has been sometime since i have looked through the service manual however.
The manuals on the M16/M4 discuss accuracy as maximum effective range against a point target. 550m/500m respectively. I have never noticed anything regarding MOA in either the -10, -20, fm22-9, nor fm3-22.9
In the 22-9 series they do talk about the 4cm circle on the 25m target and how that relates to a 19" circle at 300m. But the 4cm circle is not ht MOA of the rifle, but rather the minimum standard to be met when zeroing.
Not saying this info isn’t published, just not sure which service manual folks are talking about.
Pete
MOBG (Minute of Bad Guy)
Jack, are you looking for info on the best possible performance of the barrel and ammo, or factoring in optics and user?
I am trying to put a definable number on the accuracy of the Carbines. As to point out that these are not sniper rifles with sub MOA accuracy. What one can expect from a solid shooting position, with service grade ammunition out of service grade carbies.
I have seen guys put bipods on SBR’s and when asked why the answer was to get that perfect shot when the BG presents it.
I think they are expecting Sniper accuracy out of service carbines. That’s all, I was hoping for a MOA answer, and I thought I read in my COlt Manuals 4-5 MOA, but I will have to read them again…
Anyway ROb_S I want to discuss the game plan for next month…
Jack
From my own experiences, 4-5 MOA with surplus ammo is about the best you can expect from your average M4. I was able to reliably hit the 8" steel with my 11.5" long, .625" diameter barrel Colt at 200 yards using the mag as a monopod with xm193, which would appear to be consistent with this.
I’m buying a Harris bipod, QD mount, 3-9x scope, and Larue SPR mount to try to test the accuracy potential of my carbines and various ammo. Not sure if that may help answer your question when it’s done. I’m looking to see what each rifle/ammo combo is inherently capable of when taking the human out of the equation as much as possible.
I think that most people that put bipods on SBRs, or even M4s, are just building guns to take pictures of. Go over to TOS and take a look at their “picture thread” sometime. It’s rather humorous.
Rob,
Sounds like a good test. Let me know when you get the gear and I will try it on my gun too.
Jack
4-5MOA is what I’d expect from an AK series rifle with military ammunition.
I have NEVER seen a Colt M4 carbine that wouldn’t shoot 2.5 MOA with Greentip and under 2 MOA with better ammunition. I have seen hundreds of these rifles and I feel very confident in stating that the rifles are mechanically capable of 2 MOA with decent ammo and 2.5 with Greentip.
Greentip is great ammunition. It’s just not super accurate—it’s ultra reliable though.
I have had several commercial Colt 6920s and 6921s (14.5") and had the opportunity to bench test them. With an Aimpoint, everyone of these rifles would shoot USGI Greentip into under 5" at 200 yards (2.5 MOA). When these rifles were free-floated, used with a 4x optic, and fed MK262, they consistantly shot 2-3" (1-1.5 MOA) at 200 yards.
Out of the box, if a Colt M4 won’t shoot 2-2.5 MOA with USGI ammunition, there is something majorly wrong.
I have a friend who had a Colt M4A1 with over 60K documented rounds that was key holing rounds into under 3 MOA with Greentip at 100 yards. They were still under 3 MOA but they were going through the target sideways.
Anything shooting 4-5 MOA should have been made by a drunk Communist…
4-5 MOA is about what I get too. This is using Iron sights. I’ve seen many shooters in classes get about this same level of accuracy on the slow fire 50 yard head shot drills.
The ammo is generally the limiting factor.
U.S. military specifications for M193 Ball ammunition require a 55
grain bullet at a muzzle velocity of 3,250 q 40 fps from a 20
inch test barrel measured 15 feet from the muzzle. The accuracy requirement
from a test fixture calls for a maximum of a two inch mean radius at 200
yards from ten 10 shot groups (which equates to approximately three MOA)
NATO specifications for SS109 (U.S. M855) Ball require a 61.7 grain
with a hardened steel penetrator at a velocity of 3,025 fps from a 20 inch barrel 25 meters from the muzzle. Typical velocity 15 feet from the M16A2’s muzzle is around 3,100 fps. The accuracy
requirement from a test fixture equates to a maximum of approximately four
MOA over the 100 to 600 yard range.
Most AR carbines that I have fired from a rest are capable of 1" groups or better at 100 yards if fed something like Blackhills or Federal Gold Medal ammo. This would include Model 1 kit guns on up thru the list to the Colt.
Using US made Nato ammo about 3-4" is the norm.
Correct me if I’m wrong ,but I was under the impression the 14.5 inch M4 with a 1/7 barrel was designed to use 855/ss109 62 grain and woud preform better with that than Xm193 55 grain ammo . as such the 62 grain shoud improve accuracy .
Except the 62 grain stuff has a binary core that tends to not be quite perfectly balanced, I.E. It will be a bit heavier on one side than other because the steel insert is not quite perfectly centered. The fully lead core stuff tends to be more uniform in its concentricity.
I see. I didn’t know that.
The group I work for uses Colt’s and have for a long time. We get rather good accuracy from our blacktip AP. The best shooters get under 2 MOA with our EoTech’s with it. We practice and qual with white box Winchester 62 grain ball though and see around 3 MOA. The Federal frangible works good on the LaRue’s, but never has shot great from my issued guns. I loved the Greenshield frangible for accuracy but it flat ate the flash suppressors. This stuff made my old AR15 and ACOG seem like a SPR.
Just rambling but I enjoy the topic. 
I was under the impression that the 1/7 barrel was actually chosen so that it stabilized the heavier tracer ammo. The NATO SS109 was considered “underpowered”, so the US Military developed M855, being a “hotter” velocity ammo. The SS109/M855 was developed because of a perceived Soviet development in body armor (which never really panned out) for there forces and a need to defeat that armor resulted in the new bullet development. A very good read on everything you would like to know about the 5.56mm, types of ammo, history, development and types of accuracy, can be found here:
Not sure how well this response pertains to the OP, but I was pleasantly surprised to see near-MOA accuracy from my BM M4gery with XM193 ammo. My BM lower was blessed with a pretty good trigger pull too. This was a 100 yard target off the bench using an ACOG;
If we are talking inherant accuracy only-
I know that side by side INFORMAL accuracy testing was done by an organization of the SCAR-L, M16A4, and M4A1. This was an extremely low density test, but both the A4 and M4 were rack grade, used weapons. IIRC there were only 1 of each weapon tested. The weapons were racked and mechanically fired. M855 was used.
All were between 1.25 and 2 MOA.
The M4 actually came out on top, but not by much, and remember the low density of the test.
In a shooter’s hands, I will not accept more than 4 MOA at 100 yards (10 shot group), and I expect around 3 MOA (rack-grade weapons, not purpose-built). With SPR type I expect 2 MOA from the shooter/weapon.
I have an older BM M4A3 which now has c. 9000-10000 rounds rounds through it.
At around the 8000 round mark it was still grouping on average between 1.4 - 1.8 MOA at 100 meters with a S&B Short Dot and shot from a bipod / shooting bag support. Ammo was AE 55gr.