Home Forums Hunting & Shooting AR and Tactical Rifles Accurizing an AR

I have a Delton Mid length upper on top of a Rock River lower that I would like to make more accurate. Looking for some ideas to start. I have already free floated the barrel. Would changing the BCG help? Do I need to rebarrel? It is chambered in 5.56 I plan on using it for coyote hunting.
TIA!

A good trigger will help a lot.

What kind of groups are you getting now, and how good do you want?

What type of ammo are you using?

The groups were about 2.5.@ 100 I am looking to bring that down to MOA if possible. Might be asking too much. I used Winchester 55 gr. SP ammo. Thinking of putting a RR 2 stage NM trigger. Didn't know if the bolt carrier had much to do with accuracy. Also shooting 223 in the 5.56 chamber?

IMO, barrel and trigger are the most important components of an AR15 (assuming everything fits and all that). The rest of it just works, or not. But then there's the question of optics and mounts.

Leupold VXll 3x9x40 in RR mount. Very solid and torqued to specs . Hoping the trigger change will help. What kind of groups are you guys getting?

Better trigger and try some better HPBT ammo, 69 gr. or 77 gr. if barrel twist allows.

1x9 twist. Don't know if it will stabilize. I have a ton of 52 gr. Matchking bullets to load. Haven't tried them in this rifle yet.

its easy as 1,2 3... buy a good barrel, put it in, shoot good groups....for me IIRC about 1.25 MOA or better for 10 rounds

first try different ammo

A 1:9 barrel should stabilise 69 gr. bullets.

Better trigger and for sure try some better ammo. Get some Fiocchi 50gr vmax or some federal 69gr match.
If it won’t shoot those then you can start looking into the rifle

Trigger barrel and load, then check out the black rifle thread here and practice shooting 10 shot groups. That about covers it.

1 in 9 will stabilize a 73 grain pill.

There's no accurizing an AR, per se', IMO; there's only building it right the 1st time or re-building it right to fix it.

Then there are tweaks, which are being discussed here, nothing more, nothing less.

Most of those are not going to really "accurize" an AR.

MM

Ordered a RR varmint nm trigger. Going to pick up some 69 gr. Sierra Matchkings, load them up and see what I get.

Those 69gr SMK bullets are a great choice, and should be a good match for that 1/9 barrel.

When I first got into building accurate rifles, an old gunsmith taught me the "3 B's" of accuracy - Barrel, Bedding, and Bullets, and that everything else is secondary. In my experience that applies to an AR as well, assuming we're starting with a free-float barrel system anyway.

- A good accurate barrel is the heart of an accurate AR. For accuracy, a free float handguard system goes hand in hand with that.

- The "bedding" part is the fit of the barrel in the upper receiver, and in my experience there is definitely a difference between a loose fit and a very tight fit. I like the BCM interference fit uppers best for this (you heat up the upper to fit the barrel extension into it; it's basically a press fit). Loctite or epoxy to bed the extension in a looser upper is next best, and a drop in fit assembled dry is at the bottom. Strictly speaking to accuracy here, not reliability or function.

- The importance of bullets is obvious to anyone who loads their own and has worked up an accurate handload. If you don't load your own, experiment with as many different types of quality ammo as you can get, and buy a bunch of the most accurate load. You may want to write down the lot number of that ammo if you're real picky.

A good trigger, gas system tuning, stock and optic choices, etc all matter too, but IMO the three things above are the platform to build an accurate rifle on.

Had a rifle with the same issues, put an Oden barrel on and a RR trigger and it’s under an inch with good Ammo. 1/2 inch groups are not uncommon

Do not dump the barrel until you know its the issue. Its rare to see a barrel that won't shoot MOA or scare the hell out of it with the RIGHT ammo.

I have a smith buddy that has always shot 9 twist on purpose and he shoots 80s through them... you won't know the heaviest until you try it.

Federal Gold Medal match 69s is one thing I"d buy a box of. If they don't shoot better than your current, that might be a sign. Others have great luck with the other loads mentioned.

IIRC, and its been years since I played a lot, a 9 twist might stabilize an 80 but not a 77 due to bearing length... again you wont' know till you try.