AR accuracy issues

[Mattog22]

I have an 18" govt profile barrel I just put a free float tube installed on it. I had really only plinked with it at shorter ranges before I had this done. I put I 4-12X Bushnell Trophy scope on it to see how it grouped. It seems like I can sometimes get about 3 or so to stay within about 2 inches then I will get flyers causing my group to open to about 5 inches. The group opens up all over the place, not just low left or something like that. I was shooting Federal FMJ ammo and some FMJ reloads. I'm pretty sure the scope is good since it was working fine on the gun I took it off of but I will still try a different scope as well next time I go out. I will also try better ammo too, but my concern is that even with FMJ ammo I feel like I should get better groups than I am. Any suggestions on what to check before I go out next time with better ammo then switching scope?

Thanks,

Matt

[00bullitt]

It very well could be the ammo you are shooting. It just might not like it. It could also be something with the installation of then FF handguard. Barrel nut not tight enough. Gas tube is not centered. Pressure being exerted on the gas block or gas tube. The crown may have an issue.

Make sure the scope is mounted securely to the rail and the mount it is in.

Check those things and see if anything is apparent.

What kind of FF tube did you use?

[Bryan 45]

There are a lot of things that could be going on, but did you have to re-install a muzzle device after you put the tube on? I've seen muzzle devices that are too tight cause erratic groups.

[Mattog22]

There are a lot of things that could be going on, but did you have to re-install a muzzle device after you put the tube on? I've seen muzzle devices that are too tight cause erratic groups.

I didn't install it myself but I will break it loose and retighten to check it out. Thanks for the suggestion

Matt

[warpspeed]

I'm guessing you don't have go / no-go gauges but they are the first thing I'd check. Then the crown. You should be able to see of the bullets are tipping in the comp pretty easily.

Also, get yourself a box of Federal Gold Medal Match ammo. Yes its pricey but I've never seen a gun it would not group in short of a 1-14 twist one. If that won't shoot, it's the gun. If it will, it's the ammo you have.

[Powder Finger]

I have an 18" govt profile barrel I just put a free float tube installed on it. I had really only plinked with it at shorter ranges before I had this done. I put I 4-12X Bushnell Trophy scope on it to see how it grouped. It seems like I can sometimes get about 3 or so to stay within about 2 inches then I will get flyers causing my group to open to about 5 inches. The group opens up all over the place, not just low left or something like that. I was shooting Federal FMJ ammo and some FMJ reloads. I'm pretty sure the scope is good since it was working fine on the gun I took it off of but I will still try a different scope as well next time I go out. I will also try better ammo too, but my concern is that even with FMJ ammo I feel like I should get better groups than I am. Any suggestions on what to check before I go out next time with better ammo then switching scope?

Thanks,

Matt

I would lean to the gas tube cock-eyed also especially with a new float tube installed.

[gerritm]

I shoot the Federal FMJ ammo and I have found it to be very inconsistent in accuracy. Try better quality ammo. Also if you are not using a solid rest or something like a lead sled it might help with the groups.

[jaggy13]

I just had the same issue this weekend, went out with the intent of throwing a 200 yard zero on my rifle and ended up troubleshooting flyers.

Thanks for the post, I'm checking my gas system and looking for anything out of the ordinary on mine now.

For what its worth, I had bulk ammo I started with and then moved to hand-loads that were giving sub MOA out of another rifle.

[AlamoShooter]

I don't know much , but the first place I would be looking at is your scope rings . how did you mount the scope? I think the Ar will give scope rings a harder ride than most any other gun.

[bigbrowndog]

there are way too many variables to be able to give you a definitive answer,

including some of the reasons already given, Bad shooting position (the support or yourself), magazine making contact with support device upon firing, muzzle crown defect, loose brake, scope mount bad or improperly mounted, bad scope, improper torque on FF handguard, poor ammo, wrong twist in barrel, etc.

Given a good quality optic, my first look would be at mounts and shooting position. try having someone else shoot the gun, and do it from a position like prone.

trapr

[George]

A heavy, creepy trigger can cause a flyer now and then too. If you have a nice, crisp breaking trigger that isn't stagey as you take up the slack then ignore this.

[Jin]

most issues i have run into are mount/ring related.

mark your rail where the rings/mounts end or begin with a pencil...to see if you have any movement.

Edited December 15, 2010 by Jin

[Bongos]

Can you be shooting 55gr out of a 1:7 twist gun, if so try heavier bullets like the 69-77gr.

1:8-1:9 twist is better for the 55gr

[stewj]

how does the gas tube change the accuracy?

[Sc0]

FWIW: My AR10T shot like crap and after I ordered a new barrel/forend/gas system I noticed that the factory floating hand guard was hitting the back of the gas block... Something easy to check.