I could look for a firearm user group, but i know you guys... I'll find one if no joy here.
I bought a used DPMS AR10 and it has a problem. It leaves the spent brass in the chamber and slams the next cartridge into it. We exchanged the entire extractor/bolt assembly with another rifle. the problem follows this assembly.
Anybody know of a trouble shooting guide for the AR15/10 line of rifles? Or what parts to replace for this issue?
Karl
Karl Townsend wrote in news: snipped-for-privacy@4ax.com:
Check out:
A few possible sources of your problem:
dull or damaged extractor
weak extractor spring
ammo (mostly reported with steel cased stuff)
rough chamber
The last two are unlikely if it's fixed w/ a bolt swap, but if the first two are marginal, they could be agravated by the last two.
Doug White
Tell us about your ammo.
My son was working on the issue. He gave up. I'll try different ammo to be sure. But, he thinks its in the bolt carrier assembly, somehow. he wanted me to buy an entire assembly. Too much bucks.
I found these schematics on the DPMS site:
(I put them here so I wouldn't lose them)
Karl
Are you using ammo that has the correct pressure curve for use with a gas operated rifle?
Wes
Can't really see much from that picture, but I'm going to suspect either a broken extractor spring, or a worn extractor, either of which could be allowing the extractor to slip off the rim rather than extract the shell. I'd think that the spring and extractor should be like $10 worth of parts.
You got a good point. I'll just order these and a couple other of the cheap parts. Clean and replace. Good step 1.
Karl
On an AR15, this behavior is because of a bad extractor, weak extractor spring or missing extractor plug. Not sure if the AR10 has the last, it's a kind of stiff rubber plug that sits in the center of the spring. Keeps the hook of the extractor in contact with the rim of the case during the unlocking phase. There's a specialty D-shaped O- ring that can be had to add even more force if the original spring and plug aren't enough, "D-fender" IIRC. Not sure if it fits an AR10, though. AR15.com is the place for further inquiries, though. Make sure the ejector plunger isn't fouled by a lot of brass shavings, too.
Stan
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