AR .260 chews 'em up and spits 'em out...

Predator Strikeforce

Predator Strikeforce

New member
553312_418469401530237_68737158_n.jpg


My DPMS LR .260 has been having some issues. I need the AR experts and guru's to chime in here. Here's a list of the current issues.

1-Chewed-up and bent firing pin retaining clip. Less than 1000 rounds through the gun and this is the third retaining clip I've had to replace. Obviously somethings not right.

292344_418469758196868_911082517_n.jpg


sideview
206181_418469864863524_1322482021_n.jpg


2-Chewed-up and broken gas rings on the bolt assembly itself. A large section is completely missing.

602456_418469211530256_1355356544_n.jpg


3-Unusual looking primers. They appear to be pierced. This occurs about 50% of the time. Sometimes they shoot out a tiny little ball of debris which gets ejected or lodged in the bolt carrier.

307039_418469511530226_677526212_n.jpg


I can't help but think that maybe it's all firing pin related. Like possibly the firing pin is striking the primer too hard which bends the retaining clip allowing the primers to get pierced. I've repalced the firing pin already and nothing changed. Looks to be perfectly fine and normal too. Really, I'm totally clueless at this point. Please help and thanks...
 
That sure is funky and I hope someone who knows more than me can help you out....

When I got my lr-243 it had a handful of funky problems (not the same ones as you've got). I threw an adjustable gas block on it and it solved every one of them... haven't had a single problem since. Who knows.....!
 
Hey Tom,
I'm not an expert, but have had some experience with your problem. First, the "blanking" or piercing of your primers is most likely causing the subsequent damage to your bolt pieces. Gases from your pierced primers are flowing backwardwards into your bolt components. Check your loads, you are either running them too hot or you need to switch to a harder primer. I used to see this a lot when I was using Federal 210's or 210M's. I'm also assuming your firing pin was designed for use with the .260 and your bolt so firing pin protrusion is not excessive.
Once your primer/load problem is fixed, check your cases. If there is a line around the case just above the extractor groove, there is a chance your cases have stretched too far and case separation may occur- not good. You can straighten out a paper clip and run it on the inside of the case and "feel" for an indentation on the inside of the case to confirm. You may be able to just look inside the case for a line.
Hope this helps

Kevin
 
Thanks for the advice thus far fellas.

Scott, I'll be anxiously awaiting your call.

I've tried handloads and four different factory loads from four different manufacturers. That's why I never imagined that the problem could be the ammo. I'm not dismissing anyones advise at this point. I hope to find the culprit soon.
cry.gif
 
Originally Posted By: Predator StrikeforceI've tried handloads and four different factory loads from four different manufacturers. That's why I never imagined that the problem could be the ammo. I'm not dismissing anyones advise at this point. I hope to find the culprit soon.
cry.gif
 
I had the exact same problem with my DPMS LR308L. I sent it back to DPMS and they replaced the barel and that solved the problem.

Good Luck
 
I think you should try a go-nogo-gauge. Chamber might be a bit tight... I wonder if your bolt looks like it is all the way closed but it is just not quite there.

but looks like pressure for sure.

yeah, just looked at the pics again...looks like your bolt isn't locking up all the way and the BCG is taking a beating.
 
Last edited:
Originally Posted By: bushy


yeah, just looked at the pics again...looks like your bolt isn't locking up all the way and the BCG is taking a beating.


The AR rifle will not or atleast should not fire if that is the case. Mine will not fire if the bolt is not closed all the way.
 
Strikeforce,

You have headspace issues...this is not a load issue, if you are getting the same issue with factory loads.

I'd send the upper or barrel back to the manifacturer.

Best of luck.
 
Back
Top