AR mods for accuracy

[mongo4567]

I have a lot of ARs, small and large frame, and they all will shoot MOA with the right ammo. The best upgrade to me is a drop in single stage trigger.

I had one ar15 in 556 with an 18 or 20" barrel and a 7 twist that aggravated me. It would only shoot cheap 55grn really well; would shoot all the match 69 and 77grn stuff at 1.5 to 2 MOA. I replaced the barrel with a bergara 16" and shot this with my first handload. It shoots most everything I try.

Same thing with an AR10 in 308 with a 10 twist. I could never get it to shoot anything in the 150grn range really well. It loves 168's though.

 

[Orange Dust]

This is what I have done to my .223 wylde. I built the upper myself. It has an Odin works barrel and billet upper. I squared the upper in a lathe and bedded the barrel extension into the receiver with blue loctite and used a free float handguard. It is sitting in a Spikes Tactical Gen II Lower with a great trigger and it is adjustable to take out all the play with the upper. I think the most important thing is the union between the barrel and upper. This whole package wasn't cheap, but I built it over time. I have never found a handload that would shoot over 3/4". It will shoot 68gr Hornadys in a ragged hole. I have a 6.8 built the same way with a 3R ARP barrel that will do the same thing. Isn't rocket science, its Barbies for men.

 

[jpndave]

As long as we're talking decent parts installed correctly,

• Trigger - hard to shoot accurately if you're pulling gravel. I prefer TriggerTech
• Barrel - doesn't have to be epic to shoot well but decent. Lately really liking Faxon SS bang for buck it's not Bartlein but very good
• Rail (floated and not touching the barrel forward of the barrel nut) I prefer BCM first then Aero
• Ammo - I handload mine but there is a lot of good factory stuff out there. If you buy junk that's maybe mil spec that's how it will shoot, if it feeds

If any of those pieces are not right it's probably not going to shoot tight. After that you can really dive down the rabbit hole.

My DMR build 6mm ARC. It should be a very accurate fun yote gun. Might let my son hunt deer with it this year too.

 

[aschler]

This is spot on.

Keep in mind that AR's were designed for practical/combat accuracy not precision. If you want accuracy look at a stainless steel barrel as opposed to a high carbon or Cold Hammer Forged barrel which are meant to be durable for high round count but typically have a chrome or similar coating on the bore which can be inconsistent. Free float the barrel for best accuracy just like a bolt gun.

Triggers make a big difference, there are plenty of good triggers out there but I tend to go Geissele for my guns that may save my life one day. Trigger Tech has some offerings I would consider for a precision build.

Good ammo is good ammo. Lots of ammo out there is 55gr which is meant to be shot out of a 1:12 twist barrel but most AR's on the market have a 1:7 or 1:9 twist barrel for use with heavier bullets. Make sure you are matching the appropriate weight to your twist.

Lastly just make sure there is a good overall fitment of parts. AR's weakest point in my opinion is the front of the receiver where the barrel and the receiver and the handguard are all trying to thread and clamp together. Make sure everything there is good and tight, or eliminate it with some kind of monolithic upper.

My chrome lined Criterion and nitrided BHW barrels are more accurate then my stainless steel Proof and Satern barrels.

 

[Old Rooster]

When I built mine the rifle shot well over 1 inch.I borrowed a frieds lapping bar and squared the receiver to the barrel and accuracy improved.
It will now shoots better.

 

[KSB209]

Lots of good intel. Thanks fellas.

I'm not looking for 1/2 MOA rifle here but would like to see MOA or better. I don't reload but do like Black Hills ammo. When I'm out in the desert having fun with large targets I have 1000's of rounds of mil spec stuff that I can "spray and pray" with. But when I want to be more precise I do shoot Black Hills or Hornady match. With better ammo I do see better groups but I cannot remember ever getting under 1.5" with my AR.

I have bolt guns that shoot 1/2 - 3/4 MOA all day when I do my part with factory ammo. One of these days I plan on sitting down and rolling my own ammo. I have all the components just lack of time right now (work + 3 kids).

 

[biednick]

Once you have a good barrel and a free float handguard, lapping the upper and bedding the barrel with loctite can help squeeze a little more accuracy out of an upper. Getting a matched bolt/barrel will help too. On the lower, a good trigger is critical followed by a comfortable stock that fits you and a grip that you can hold without wrapping your thumb around the back.

The fit between the upper and lower isn't critical, but if it's too loose you might have issues building a stable shooting position.

Ammo is also critical. Bulk ammo won't shoot well, you'll do much better with factory match or handloaded ammo.

Of those elements, the barrel, ammo, and trigger are going to make the biggest improvement. The rest will let you squeeze a little more precision out of your rifle, but probably won't make a huge difference.

 

[Lefty38-55]

Here's what's works for me, besides some the basics listed previously:

Adjustable Gas Block - Besides adding a good trigger, I get the most bang for the buck with one of these. I even put on into an 18" upper of 7.62x39mm chambering and when tuned to the bulk ammo it likes, it shoots 1-1/2 MOA out to 200-yards, the furthest I've taken it. Using good PMC soft-point ammo (that I use for hunting) betters that and almost makes it into a 1 MOA rifle. Amazing really!

Triggers - I LOVE the Geiselle SSA-E triggers! I am an unabashed supporter of 2-stage triggers!

Cryogenic Treat the Barrel/Action - Not applicable to an AR per se, as I have not had one myself that 'spread' the shots as the barrel heated up, but I had a Romanian Cugir PSL (a Russian Dragunov copy) in 7.62x54R that would wander shots up and to the right as that pencil thin barrel heated up. I sent the barreled action out to the cryo house who has an FFL and when it came back, I loaded up four 10-round mags and did a mag dump as fast as I could reascertain a good sight picture and the group stayed in the black !!!! no wandering impacts!

 

[Greyfox]

Within the limits of the cartridges/range, I agree that a well constructed AR can be surprisingly accurate. Attention to ammo, trigger, headspace, and a good free floated barrel can easily deliver .5MOA accuracy, sometimes better. While some shooters claim they see little effect, I am a stickler for a tight lock-up between the upper and lower, having found that accuracy can be effected by a sloppy fit.

 

[bamban]

As I have mentioned in various threads that I do our TX JRs AR15 competition barrels from donated Shilen blanks. Our kids' level of expertise vary from Marksman to High Master. To ensure we issue the best barrels to the top shooters, we test the barrels at 600 yards.

To facilitate ease of testing on the solid machine rest, I came up with Remington bolt gun adapter that we can screw on AR15 barrels without the barrel extension.

The bedded stock is shortened enough so we can clamp the barrel and spin it off with a side entry action wrench without taking the action out of the stock. Barrel swap is like a 10 minute job.

In the past we just we just randomly issued barrels, we could have easily issued the best barrel the starting shooter who will never see the potential of the barrel.

Our top tier juniors are winning matches. 490s in the EIC matches, 790s in Regional course matches.

Note: What looks a thick washer/ring is the recoil lug in function.

 

[436]

Thanks for all the suggestions.

One more, you might think about a clone M262 Mod 1 .77gr OTM I've found this load (my reload) works great in both short and long barrel ARs producing sub-MOA in a good rifle, with 1-8 or 1-7 twist barrels. Good luck... Cheers

 

[mtwarych]

My son and I started our long range career shooting gas guns. I had a brand new DPMS GII and my son had a brand new DPMS AR-10 ( I believe it was DPMS's "Recon" model) chambered in 308Win. My GII is chambered in 7.62X51. We can't shoot each others reloads. Anyway, without sounding like a know it all pud, my biggest accuracy improvement came from learning how to mount and shoot a gas gun properly. Once I learned how to set myself up on the rifle, crack the primer and watch my impact through my scope, my GII is scary accurate. So is my son's Recon.

 

[TXAoudadKlr]

I'm getting consistent 1/2 moa with both of my GAP-10's

My BCM SPR upper is more in the 3/4.

I firmly believe the barrel is the heart of an ar and the accuracy starts there. My two GAPs wear bartlien barrels. My BCM is just a hammer forged but has a "match grade" chamber and does extremely well with the 69 and 77gr ammo from black hills.

I am quite fond of Geissele triggers I have both the SSA-E and the SD-E (flat) triggers

I really like the SD-E the best, feels lighter and crisper with the pull weight being essentially the same