AR accuracy issues

[jmg8550]

I have tried shooting groups resting the rifle fore end on a rest with similar results. I have not had a chance to test it with the ammo DPMS suggested yet. I will pick up some match grade ammo and see what happens.

[Irving]

You said you already did this, but here is an article you may find some what relevant.

http://www.theboxotruth.com/docs/bot51.htm

[ldmaster]

I once had an inaccurate rifle, along the lines of what is frustrating you.

Spent a lot of time on it.

Finally I realized that I was investing lots of time and stress in a 400 dollar problem. So I sold it, bought a new one - problem solved.

I used to be obsessive about getting my guns to shoot well for me, I still am, but realize that my time is worth something and some guns are just money pits.

If you've ever seen a barrel made, you probably know that a lot of it is done by hand, barrel blanks that have been bored and rifled are NOT 100 percent straight, they have to be straightened by an experienced barrel tuner. Then checked with a couple of instruments. Sometimes the tuner messes up.

Things you might want to check:

1. Your barrel crown. Even though you have a FH on it, it might have a few nicks in it (use a jewlers loupe and see if your lands and grooves are concentric and even. this is the most common problem with barrel inaccuracy, and nobody ever seems to check it.

2. Any torque placed on the barrel from the gas block interface with the handguards? Take the hanguards off to check. Think of it as a cheap free float!

3. Swap bolts with any other AR and see if you get the same results. We'd all like to think our bolts are true and mate 100 percent, but that's not always the case.

4. If you're handloading, drop velocity to 2700 at the muzzle. Sometimes the powder/primer/case/bullet combination is just wrong for YOUR gun. I was hugely frustrated with the accuracy of 40S&W ammo when it first came out (remember it's a neutered 10mm) and all the loadings were 180gr for practice. So I worked up a 155 gr load with alliant power pistol and small rifle primers. Worked very well and became a pet load of a local agency that used to reload their stuff for practice.


But personally, I'd just sell the thing if it isn't working well. DPMS PROBABLY swapped your barrel out, which may have done the trick. They don't waste a whole lot of time on this stuff, they just replace things until it works well and get it out.

[jmg8550]

DPMS didn't replace anything. They test fired it and sent it back with a copy of the target. It really liked Federal Match 69gr.

Here is a picture of their target:

[buckshotbarlow]

i had the same issue with a bad shooting 308 from savage. Once i found the chamber depth, and seated the bullet just touching the lands it went from 1moa to .5moa just like that. Try finding the land depth, then seat just off the lands and work forward to the lands. It might turn your gun into a single shooter though...

[jmg8550]

Anyone notice the date on the target. I was just walking by it on the counter in my apt. and saw the date on the target is 8/20/2011. WTF? that date hasn't even passed yet. Also, why is the target a photocopy? They couldn't send the real one?