Gunsmithing LR308 extraction issue

[aride4ever]

Hi guys/gals I was hoping someone with some insight in to LR308
I have a LRT-SASS with an issue I have not experienced before with my other LR308. Whats happening is after aprox 30-40 rds I will get a failure to extract, the bolt carrier pulls the casing about 1/2 the way, the next round slides into the extension and gets bent. This causes neither round's or the mag to be easily extracted. I have seen several threads on similar issues but non seemed an exact fit. I have had 2 smiths look at it and not be able to resolve this. attached is a pic of the rounds,these are federal and Winchester but it happens with anything except AP

 

[woodspider]

Re: LR308 extraction issue

Does it do this with many different mags or are you using same mag all the time?

 

[normbal]

Re: LR308 extraction issue

Failure to EJECT, not extraction problem.

Takes 30-40 rounds to start? Every time?

Sounds like a gas problem, like major leakage somewhere.

I had problems like this with an FN-FAL, shot it at night to see where the gas was escaping. ARs have similar places to leak from, but not THAT much.

It can't be recoil spring, extractor spring, but maybe the mags? I have this issue with two DPMS AR15 lowers if I load up magazines to 30 round capacity the same thing happens. If I only put in 25 rounds, no problem, but that's with the first round, it gets BETTER later.

So you run what, two mags full through the gun (assuming 20 rds) THEN this starts happening? Try numbering your mags and see if, when topped off, any one particular mag is doing this.

 

[hondo1312]

Re: LR308 extraction issue

I have the same issue. The first time I thought it was an extractor issue, so I bought the dpms parts kit and had a smith replace it. It worked fine for about 50 rounds, then started having the same issue again. I was using p-mags and I've had it happen with FGMM 168s and remington 150gr core-lokts.

I don't have a solution, but at least you know you're not the only one with this problem.

 

[aride4ever]

Re: LR308 extraction issue

thanks for the hit's, I am using DPMS 19RD mag's and I have had the same issue with the P-mags. It has been doing this with factory ammmo and I was hoping to get rid of it before I started reloading. One thing i have noticed is that for the most part the first 20-30 rds are being ejected clean, no carbon or such however when the issue presents itself the casings look like they have been burnt with a soot on it. Normally I wouldn't be critical of this but at this point im at a loss. I will see if I can narrow it down to a specific mag as suggested. thanks for the feedback.

 

[aride4ever]

Re: LR308 extraction issue

just wanted to update you on the findings, I spent the good part of yesterday at the range trying different mags and ammo, it seems I have narrowed the issue down to one a specific round. Winchester bonded and a C-product mag. When I swapped either component I no longer had the issue. I noticed that the bullet was longer than the federal I use and when the Winchester rounds were in the C-mag it would catch on the feed lip. I used a bore scope camera to witness this. Thanks for the info's

 

[normbal]

Re: LR308 extraction issue

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Aride4ever</div><div class="ubbcode-body">just wanted to update you on the findings, I spent the good part of yesterday at the range trying different mags and ammo, it seems I have narrowed the issue down to one a specific round. Winchester bonded and a C-product mag. When I swapped either component I no longer had the issue. I noticed that the bullet was longer than the federal I use and when the Winchester rounds were in the C-mag it would catch on the feed lip. I used a bore scope camera to witness this. Thanks for the info's </div></div>

Thanks for the update.

Bore scope?

I trust you had the firing pin removed during this operation.

Glad to hear it's not the gun, specifically.

 

[aride4ever]

Re: LR308 extraction issue

yes firing pin was removed I am heading out to the range again today as im interested in knowing if the 3 C-product mags have the same issue. I ground the tab down just a bit on the mag and from what I can tell it seems that the rounds fit proper. One thing for sure is that the mags don't like the full 19, the last round seems to shift slightly due to the tension.

 

[powderBurnz]

Re: LR308 extraction issue

Are you running a stock barrel? Or is it something special with a tight chamber?

A real simple/cheap thing to try is get a d-ring and throw it under your extractor.
D-Ring