Accuracy issues with bull barrel rock river arms ar15- Tulsa ar builder to trust?

[czechnolike]

Greetings all,

I bought a bull barrelled, 18 inch, 1 in 8 twist AR-15, rock river arms, from the big Tulsa gun show.

It has an awesome trigger, psg1 grip, and excellent stock. Love the idea of it.

I cleaned the Barrell, and have shot about 12 different type of ammo through it. It's not liking much! 1 to 3 moa groups. Switched scopes and mounts too.
Very inconsistent.

My rock river arms LAR15, with a gov barrel, eats 55 ball ammo all day with around 1 inch groups. No problem.

Who in the Tulsa area is reputable to trouble shoot an AR? I figure it's with having a check over for torque, worn parts, etc. before going to the next step

Anyone have Crusader tactical or Advanced combat troubleshoot accuracy issues?

Or do I have a worn out barrel? This AR must be 15 years old. Don't want to dump a bunch of money into it, but definitely open to a new barrel IF that is the problem.

Pics, Bull is the bull Barrell ones. 16 is the rock river arms 16 inch operator. That thing just rocks the ball ammo! 77 match as well.

100 yard groups, 40 degree day, little wind.

Also note, I have a Remington 700 varmint 223 that will stack a dime at 100 yards. I can normally get a quarter out of it. Some of this problem may be me the shooter, but not all.

 

[Blackdog]

Is the crown good?

 

[czechnolike]

Is the crown good?

It looks fine, and Has a 8 point gunpowder star on it now.

 

[crispy]

I have that same barrel. Except mine has a step down inward of the crown.

Edit: I saw you said 18 inch barrel. Mines a 24 inch

 

[Shinneryfarmer]

???? Their is a problem, don't know what. I have the exact same RR arms AR 15, with 69 gn match kings it will shoot under 1 MOA at 200yds. Have made 5 shot groups of less than .300 but .375 is about average at 100 yds if I do my part.

 

[czechnolike]

???? Their is a problem, don't know what. I have the exact same RR arms AR 15, with 69 gn match kings it will shoot under 1 MOA at 200yds. Have made 5 shot groups of less than .300 but .375 is about average at 100 yds if I do my part.

I wonder if the barrel nut or something is loose? Someone may have just shot it out too. Tore apart and cleaned the bolt. Seemed fine, but I don't have any gauges to check anything. Not sure any shop in Tulsa specializes in accuracy.

 

[swampratt]

These people with the same barrel are they hand loading or shooting store ammo.
Sounds like you are shooting store bought ammo.

I purchased a Savage axis used and the person gave me 4 or 5 different kinds of store ammo and said none of it shot accurate and if I found a load that worked to tell him.

I hand load my own ammo and it shot under 1" but that store ammo was 2 and 3 times the size groups of my ammo.

I took the store ammo apart and everything checked near perfect except for it was crimped and that crimp was not consistent.

After putting all that store ammo back together and eliminating the crimp and getting neck tension all the same it shot 1/2 the group size as it did out of the box.

That accuracy issue with store ammo in my rifles is what got me into reloading.
It could be it just does not like what you are feeding it.

 

[ClintC]

Store bought ammo will vary from lot to lot. bought 2 different boxes of Berger ammo. Yes Berger. One box would stack at 1/4 at 100. The other lot would do 3/4 at 100. I would have done the same at you and blame the rifle. But I had a chronograph when I seen it. the ES ( extreme spread) was all over the place from shot to shot. This was done out of a bolt rifle.

im also just going to say it. It’s an AR gas’s gun. lots more vibrations and moving part when the rifle is fired. This will affect accuracy too. Made sure the upper and lower are tight together. Then check to make sure everything else is tightened. If your getting 3/4 or better out of an AR your doing good in my opinion.

 

[Forgalspop]

I have come to the conclusion that no two barrels are exactly the same, even by the same manufacture. Each barrel can have slightly different harmonics.

I have a Savage .243 that I have tried different ammo, different powders, different bullets, crimping vs. not crimping, annealing vs. not annealing, different seating depths, full length sizing vs only neck sizing, etc. and yet I cannot get tight groupings out of it.

I have a cheap Mossberg ATR100 in .270 that will group better than the more expensive (model 12)Savage .

If I were more anal, I might try getting into trying to adjust the harmonics of the .243 barrel. Just not worth the time and effort for me. I will just live with it. It still shoots well enough to be in decent groupings at 200 yards. Just not great.

A couple links to interesting articles about barrel harmonics.

https://www.varmintal.com/atune.htm
https://www.varmintal.com/amode.htm

 

[czechnolike]

These people with the same barrel are they hand loading or shooting store ammo.
Sounds like you are shooting store bought ammo.

I purchased a Savage axis used and the person gave me 4 or 5 different kinds of store ammo and said none of it shot accurate and if I found a load that worked to tell him.

I hand load my own ammo and it shot under 1" but that store ammo was 2 and 3 times the size groups of my ammo.

I took the store ammo apart and everything checked near perfect except for it was crimped and that crimp was not consistent.

After putting all that store ammo back together and eliminating the crimp and getting neck tension all the same it shot 1/2 the group size as it did out of the box.

That accuracy issue with store ammo in my rifles is what got me into reloading.
It could be it just does not like what you are feeding it., but my

Maybe, but my other AR and Remington sure don't mind store ammo. Just get the right bullet weight and they're fine .