DPMS LR 308 jamming

T

txagyotebuster

New member
my buddy recently bought a dpms lr 308...i think it's a 16" barrel, not exactly sure on the model number....but it has the slick side (no dust cover, shell deflector, for. assist)

anyway...it is not functioning correctly. load up a mag and shoot and on about every other one it will "double feed" that is it will not eject the spent case but will try to strip another round off the top of the mag, so the empty case and the loaded round are both trying to be pushed into the chamber at the same time. when it does eject the empty it strips off a loaded round from the mag perfectly. it seems to be more of an ejection problem.

another thing it does is if you single load it (one in chamber and none in mag) when it fires it will not kick out the empty case, but will lock back the bolt, so the empty case is just rattling around in the upper.

he and i both have done some research on the web and the weird thing is on the dpms forums this seems like a typical problem, but i have not heard of it on arfcom. i have read that it could be that the chamber is rough causing the case to slightly stick in teh chamber and the extractor losing a grip on the case causing it not to fully eject.

if any of you have a clue of what it could be and a fix i would greatly appreciate it.

thanks
 
May need a new extractor. A little chamber polishing probably wouldn't hurt either. I've seen cases for both causes, but primarily, I believe you have an extractor problem.

i'm sure the experts will be more of a help though.

Barry
 
Like Barry said, extractor problems, usually a weak spring. Their 308 cheapy models are exactly that. I usually take them, polish the feed ramps, put a decent mag spring in and do a reliability package to it, which includes heavier extractor spring.
 
Your problens are the same my Brother in law had with his R25 in 243,
He called Remington and they had him send the whole gun back to check out the problem. Haven't heard from him about it lately but will check tomorrow.
DPMS makes the R25..
I'd check with the factory. Seems to be a hit or miss problem.
Kinda odd seeing two cases one loaded and one fired both heading forward at the same time..
Later

DF2
 
I bought one of those when they came out awhile back and had alot of jamming problems. The only thing that worked for me was shooting handloads or commercial 165grn and heavier hunting loads. The cheap milsurp and wolf ammo doesn't have enough punch to kick the bolt back all the way. I ended up selling the gun and getting a Bushmaster alot better fit and finish.
 
i thought too that maybe it was not cycling the bolt back all the way, but when you shoot it single shot the bolt locks back. if the loads were underpowered or the gun was under gased i would think the bolt would not lock back? i could be wrong however...

an extractor spring sounds like a pretty cheap and easy fix...however what kind of spring would you suggest???

would a new spring from DPMS be just as weak?
 
txagyotebuster,
Its very hard to diagnose a problem without putting hands/eyes on the gun/upper. It sounds like a simple fix, but without seeing it, I'd hate for you to spend the money on a new spring and it was 100% mag related.

We diagnose and do repairs, but have about a 2-3 wait on these such things. If I can be any assistance to you, feel free to call/email me.
 
I'm with Barry on the extractor being weak or damaged. A good extractor should rip the rim off before it lets go of the case. From the sounds of it, it's not short stroking. If you buy an extractor/spring and it doesn't cure it, you've still got spares, so it's not a total waste either way.
I'd say that's a high percentage it will fix it and it's one of the cheapest things to rule out.

edit: Here's something I found on troubleshooting the DPMS:

Quote:Hows the tension on the extractor? Will it hold a round? Does it take a lot of pressure to move it. It should be relatively stiff. If you took it apart to clean it, did you assemble the springs correctly add or lose the Oring?

How about the ejector? Does it move freely? make sure there is not brass binding in the hole- a problem with softer fed brass. If you load a round and manually eject it, does it fling it out the side or does it just fall out of the chamber. Check your EJECTOR and spring to see if you have proper tension and no brass shavings stuck in the ejector hole. If you're getting proper extraction (out of the chamber) and the base of the case is free of the bolt face (but not kicking the empty overboard) your ejector spring may not be pushing the case out through the ejection port before it's getting caught on the bolt's forward thrust while stripping a new round from the magazine (especially since you say you have no extractor issues and you are running a heavy buffer). This could also lead to the inevitable empty stuck above the bolt and jamming the charging handle forward (requiring removal of the upper to pull the empty out of between the charging handle and barrel extension).

 
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