Ar 10 accuracy - What can I expect?

[oldhoward]

I friend has dropped off his AR-10 to me. He is shooting 1.5 inch 5 shot groups at 100 yards. He had tried bullet weight from 150 to 180 grain and many different powders. He sent the rifle out to be re barreled with a Keiger barrel. Still shoots the same. He asked me to try it out and see if I could do better. I dont know what kind of accuracy a AR-10 is capable of, so I am asking what can I from an Ar-10 accuracy wise? It is heavy barrel in 1:10 twist. The rifle is scoped.

Thanks,
Oldhoward

 

[mao0720]

More specs on the rifle would be helpful. Who made it, what trigger, is the barrel free floated?

 

[Keith Glasscock]

1" at 100 yards should be relatively easy with a good barrel. From a consistency standpoint, you might average around there. I've seen them shoot 3/4" @ 100, but I don't know what all had been done to the rifle.

I hear tales, but have never seen a 1/2 MOA AR of any type. Considering that I have a different opinion of what 1/2 MOA means than other people do (to me it has to be consistent, not a wallet group), I'll leave you with 3/4" being a reachable goal.

Be mindful that I am a trigger puller, not a smith.

Hope this helps

 

[tonyben]

Has he tried Federal Gold Medal Match or AE 168 OTM? There's lots of variables which affect accuracy. How are his reloading skills? A 1:11 is a good twist rate and 1:10 can over-twist bullets. How experienced of a shooter is he? How experienced are you? What kind of bench setup is being used?

Is the barrel free-floated? Are you shooting off sand bags or a bi-pod?

It would be helpful to have a known good shooter get behind the trigger if you are one of if you know one.

Too many variables are involved that need to be answered.

Tony.

 

[jonbearman]

I have an ar-10 (armalite) A-2 with a scope on it. It will shoot 1/2 moa fairly easy with match loads.I use 168 grain hornady match with AA2520 powder and it will shoot under 1/2 minute off a solid benchrest rest(hart) and the proper sand bag. It has all the original parts with a chip mcormick trigger set at 3#'s. If he isn't a great shooter then all bets are off.If I use standard soft point or hollowpoints(cheapys) it wont group much less than 1 moa. My barrel is not freefloated. Ar's do exist that will shoot way better than moa,it is not a myth or propaganda. You can come shoot it yourself if you don't believe what I am saying.One thing to note is how he cleaned it and how much copper may have accumulated by not properly removing it or carbon buildup. A kreiger should outshoot mine hands down. Give a description of whatever upgrades is on the gun and we can try and help you.

 

[bsumoba]

my LR-308 is shooting sub-3/4" groups.

JP stainless barrel, BCG, bolt
bipod and rear bag
175gr SMKs or M118LR pulled 175s w/ 43.8gr Varget loaded to mag length 2.800"

 

[lightacres]

if the AR has the original factory trigger, then replace it. I have in all my ARs, it makes a big difference is group sizes.

 

[JamesnTN]

It really all depends on who built the rifle. I have a JP Enterprises that'll easily and consistently shoot sub 1/2" groups. Just this past weekend at 240 yards there was a fun shoot going on where we were shooting eggs and then quail eggs. I shot that JP against full blown custom rifles and I managed to bust my eggs and all the quail eggs where they missed. Then I sat up some tums and we began popping at them, once again the JP hung in there and busted 4 for 4 then the egg hanger got moved out to 300 yards and the JP went 5 for 5 shots on eggs. So yes they can shoot with proper hand loads and tuning.

 

[oldhoward]

Hi, The barrel is floated and the lower is a stock DPMS, with their match trigger. The 3 shot groups have been as small as a 3/8 inch, more commonlt 3 shot groups are 3/4 inch. The problem is with 5 shot groups, they open up considerably. We both are experienced shooters, and we do shoot big magnums without issues (338 up to 416's regularly) so I dont think it is recoil issue. Not sure of the barrel installer but I think he said Accuracy Speaks or Accuracy something. I think they replaced the barrel, float tube, and a few more robust parts. They did use the same bolt and fitted the barrel etc, to the bolt. Hope this info helps.

 

[fdshuster]

Oldhoward: An article in the 2014 Hodgdon Reloading Manual, by Lane Pearce, page 43 deals with that exact subject.

He lists 23 different load combinations, case, powder, charge, bullet, vel. SD & average 5 shot groups fired at 100 yards, from a benchrest.

The minimum group I'm looking at is 0.75 and the largest is 1.85.

 

[flatlander]

My experience with both AR10s & 15s leads me to believe that it's usually easier to get an AR15 in 223 to shoot consistently well than to do the same with an AR10. Just for background info, I started shooting custom SR & MR AR15 uppers in XC HP matches in '97, and eventually earned a Distinguished Rifleman badge with the SR, and NRA Hi Master classification with a MR upper. After I started doing my own barrel chambering & fitting, I built three AR10s in 6XC, 6.5x47, & 7-08 Imp 30* using Krieger & Bartlein bbl blanks, so I've got a little experience to back up that opinion. In speaking with a couple of well-known AR builders, I've been told that getting really fine accuracy with 308 bbls on the AR10 chassis can be frustrating. Not that it can't be done, but sometimes it's an elusive goal.

I recently sold a DPMS AR10 in 308 to a friend who'd expressed interest in it. I put it together with a 22" Wilson bbl that John Holliger had contoured & chambered, and initially, had been slightly more than somewhat disappointed with accuracy. During a conversation with Dave Kiff, I mentioned that John used a Obermeyer match reamer to chamber this bbl, whereupon Dave recommended that I pull the bbl and run one of my 308 match reamers in just far enough to recut the 2.5* lead to 1.5*. Had nothing to lose, so I followed his advice, put it all back together, and found that accuracy had gone from 10"-12" groups at 600yds down to 5"-6". I've got all the parts 'n pieces out in the shop to build myself a replacement for that 308 AR I sold, including a Krieger contoured blank. So I'm really hoping that it'll shoot at least as well as the 6XC & 6.5x47 do at 600.

 

[Raptor]

Flatlander is correct. Getting the AR-10 to shoot consistently good groups can be frustrating to say the least. I bought a used AR-10 Armalite and it had the std. weight barrel on it. I tried a number of loads for it and it was around a 1.5" on a good day and maybe a little less than 2" on a bad day. These were all 5 shot groups.

When I went on some of the other sights and ask your same questions I was told I didn't know how to shoot one and there were guys getting .5" groups all day long with theirs and I also needed to spend a couple of thousand dollars to get either a JP or a Gardner AR if I wanted a good shooter.

All I wanted was one that would shoot around a solid 1" at 100yds for 5 shots. I finally put a free floated hand guard on it and that really did help mine. I am sure if I put a good trigger in it I would probably be at under an inch for 5 shot groups. But with everything stock and a free floated hand guard mine will now "Average" around an inch 90% of the time with 4 ALWAYS under an inch.

What I found out was the guys getting the small groups single feed them and never shoot out of a mag. I wanted the gun to shoot well the way "I" was going to use it. I wanted a urban sniper rifle capable of putting 5 shots into or damn close to a paper plate out to about 700yds if I did my part.
Mine is now close enough for what I want it to do. I have other rifles for that long range stuff...Ha

 

[rminut]

Dennis, interesting observation regarding the 2.5 vs. 1.5 degree leade. I've noticed similar evidence with my M1a and AR10 and Berger bullets. Seems like the 2.5 leade is fine with Sierras and their tangent ogive but Berger Hybrids shot like crap in my M1a and obermeyer chamber. My AR10, barrel by WOA, is not what i'd call a hammer, i'll try to get the chamber changed over to a Bisley reamer. I also bought a Krieger M110 from Krieger because of all this.

 

[flatlander]

rminut - Guess I should've mentioned what bullets I was working with in the 308 I sold. I occasionally get the chance to shoot a Palma match, for which I've got a prone rifle built around a Nesika K/Krieger med. Palma chambered with the '95 Palma Team reamer. I had a good supply of the old Sierra #2155s when the newer #2156 came out, and had also started using a couple of the Berger 155s, so I decided to use the older 2155s in the AR10. I'd also tried a few other bullets, but those 2155s were what I concentrated on, and they're the bullet I was shooting when I compared the different throats.

I'd also purchased a Bisley reamer from Kiff, that that's the one I used in the AR10's chamber when I re-cut the leade. I'll probably use the '95 Team reamer to cut the chamber in the new Krieger - if the resulting chamber turns out to be a little too tight for good function in a gas gun, I can always pull the bbl and run the Bisley reamer in.

 

[1shot]

I picked up an Armalite AR-10T from a friend that had maybe 200 rounds through it. I mounted a Leupold Mark 4 scope on it to see what kind of accuracy I could expect and it gave me .5 moa right out of the gate with factory Hornady 110gr. TAP rounds. I then loaded some hand loaded 180 gr. JLK long tails left over from last years Palma season. Yup, .50 moa.. I have since run 168's and 185's with similar results. I think it would be safe to say it is an honest 1/2 MOA rifle. No big swings in group size regardless of the bullets that have been shot. just boreing 1/2 moa all day. Maybe I got a good one or the target series just seem to shoot a little better.
I hope this helps,
Lloyd

 

[searcher]

I have a number of Krieger-barreled A/R's and they will all shoot 1/2" or better 5-shots. Most took a fair bit of load development, none just shot that way with the first dozen loads I threw at them. None will shoot inside 1/2" with any factory ammo I tried, though that was a bit sparse. I find that the best way to get one to shoot well is (aside from that good barrel being first), put on a good free-float tube (like a J.P.), then a good trigger like a Jewel or Jard that will go down to a couple of pounds. Put on a fore-end sled such as sold for bolt guns and shoot off a rest. I ride the rear stock in a gator bag. Put on a finecrosshair or small dot scope in the 25+ power range (I use a Nightforce Benchrest scope). All of these things will help to show what the gun can really do. Forget the bi-pod and 10X scope and 6 pound trigger.

 

[oldhoward]

Thank you all for your replies and ideas. I really appreciate all of your responses.
Thank You
Oldhoward

 

[rminut]

my question is, is there a standard to judge by? For instance in a M1A you can gauge the accuracy by using "the standard" 41g of imr4895 under a 168 smk. if it doesn't shoot that there is a gun problem. Does this exist for the AR10?
i've shot this standard load in my AR10 and it was not pretty.

 

[5spd]

A pals AR10 in .243 is shooting an average of .700" @ 100 yds w/ his hand loads, and has many under .600". Not the 308, but as an all stock gun w/20" bbl. its doing darn well.

 

[people]

my question is, is there a standard to judge by? For instance in a M1A you can gauge the accuracy by using "the standard" 41g of imr4895 under a 168 smk. if it doesn't shoot that there is a gun problem. Does this exist for the AR10?
i've shot this standard load in my AR10 and it was not pretty.

No there is too much variation in all the rifles out there. You can try fgmm ammo but there is no guarantee.