DPMS LR308 accuracy problems

[CobraBob]

Pierced AR primers seem off thread; but search here; I did a write up on my DPMS and that included firing pin/primer issues and my resolution to them.

As to the OP post, Forum Boss has it right, try different ammo first. Fed GMM 168 and fed GMM 175 are benchmarks for almost all ARs. Take pics of your brass (case heads) and post them here, we can help you verify your gas system is in tune if you're not sure what to look for. Post some groups too, I'd recommend 5-round groups and 1 of them single feed, the rest feed from the mag.

Alternates to try if Fed GMMs aren't available, nosler Cust. Comp. or Hornady Match.

I'm skipping a ton of info, so keep is posted on how the ammo change goes.

-Mac

I have handloaded for over 40 years; that is my preference. $$$$ savings & accuracy point to that as the right way to go.

 

[CobraBob]

Some good advice for the OP in this thread but I still would simply start with the firing pin... It shouldn't need anything extra to make it work , it should work right out of the box with factory ammo.... I use soft CCI Primers in my AR platform rifles and have never had a problem BUT I do take every precaution still and don't have pierced primers... I can tell you from first hand experience that not all companies and builders are created equal....

One of the companies listed here is a prime example from my experience.... One rifle bought from them came in scratched up , over gassed , you have to pry the charge handel in and out , the ejector spring was garbage brand new and I could keep going.... All but the scratches I can fix right on my kitchen table and did... My point is some are problem children and I have even seen colts brand new with problems but any can be fixed easy... Most are mass production so QC is always going to be a problem... Somethings just are not checked basically and a firing pin that's just a hair to long etc will make it out of the door...

I would not send it back over a ten dollar part that takes no tools to change... Right now we are hearing horror stories about not getting guns back for months and not being able to contact anyone either... If you don't know how to fix it I couldn't think of a better time to learn... These companies way over gas guns on purpose , to keep the phone from ringing when people shoot cheap crap ammo in them , to make them cycle... So I don't doubt anything anymore... Pull it apart and take a very close look at things , doesn't cost a penny...

Great suggestions. Had not thought of the "over gas" situation. Gotta think about that as a solution, too. Softer spring, hmmm? THNX!!!

 

[velocette]

I recently tested a DPMS LR308 for a friend. It is bascially new with a 24" bull barrel, a proven Meopta 6.5x20 scope and a McCormick trigger. He is only using Georgia Arms ammo right now breaking it in. Both of us shot it with the same results. The 1st 5 shot group is an actual group. After waiting about 10 min, another group was fired and they strung horizontally about 4". The shots looked like they had been laid out horizontally with a ruler. The range was 100yds and shots were fired off of a solid bench and rest. The rifle was cleaned and the 5 fouling shots were fired before the groups. The conditions were hot and calm. Any ideas??

Horizontal stringing when fired from a rest on a bench is usually due to the rifle's butt moving horizontally under recoil. Make certain that you are squarely behind the rifle, not leaning over to reach it..

 

[Rsadams]

Great suggestions. Had not thought of the "over gas" situation. Gotta think about that as a solution, too. Softer spring, hmmm? THNX!!!

Not softer but stronger.... Try sprinco springs , their recoil springs will out last the barrel many times over... Plus you can call and talk to them , nice people if you need advice.... I don't think overgassing is your problem with the primers.. I think that is going to be either a bad firing pin or a firing pin hole that's on the large size... There's not much it can be on an AR....

Since I think your ammo is not from one of the big companies and could possibly be reloads I would try a box of federal gold medal match with 168gr matchkings bullets first , if it still does it a firing pin from a decent place like Windham weaponry or KAK industries , I mentioned both but I would start with Windham weaponry first for something like that... I use alot of their parts and have never had a problem but there's many decent places out there... That choice is yours... The odds of getting another bad one are pretty slim....

Try posting some pictures of the bolt face and the tip of the firing pin plus the fired cases including necks and heads , so we can see the heads and primers... As far as over gassed we're the empty brass ejecting if the barrel is 12:00 and the buttstock is 6:00 o'clock we would like to see it at least ejecting at the 3:00 o'clock position...