[JW1980]

Hi all, I'm new here and hope Im posting in the right place. If there is a better place to post the following question, please let me know. Thanks

I bought a second hand DPMS LR308 recently and just got out into the woods to fire it today. As far as I know it's all factory other than the rail. It was a package deal with a bunch of silver bear .308 ammo which I'm not a fan of but the price was right and its not like Its a match rifle so, I figured, what the hell.

I fired 100 rds and had a FTF about every 6th rd. Talk about annoying! the pin struck the primer each time but sounded and felt weak, as if it were only half cocked or something. I saved all the duds till the end of my therapy session and loaded them 1 by 1 charging each time by hand. Every single "dud" fired the first time using this method.

Can anybody tell me what would cause this and how to remedy it?
Thanks for the help

 

[BRL]

I had a somewhat similar problem with my new Jewell trigger unit until I figured out how to adjust it a little better.

It seems that the disconnector was not catching the hammer during full hammer retraction every time, and as a result the hammer would return almost all the way foward, but would stop just short of concact with the firing pin, as if the hammer had an additional shelf on it.

This left the hammer back just far enough that when I pulled the trigger again for the next shot, it would only fall a short distance, with not enough power to ignite the primer.

Don't know if this is of any help in your situation, but you could cock the hammer and then block its fall with your thumb so it does not fall much after the sear realises it.

At that time take your finger off the trigger, as you are lowering the hammer slowly with your thumb, and see if it travels all the way down, or if like mine, it has a shelf that stops it from going all the way forward.

In any case, don't let the hammer fall free and slam into the bolt stop or damage to the bolt stop or mag well could result!

Just an idea you might investigate, as my trigger group displayed this problem every 4th or 5th round until I adjusted it better.

This may or may not be of any help in your situation, but it's the only thing I could think of.

 

[TacticalGenius]

You could just have a weak hammer spring as well. Not sure how old your rifle is or if it was stored with the hammer back before you got it. Not to echo the AR15 too much, but bear ammo and other steel ammo does have berdan primers that are a little harder to ignite. You may need to look into a new or an Xtra power hammer spring to remedy this.

 

[TJohn]

I would go with a heavier hammer spring. My LR-308 was very inconsistent with steel cased ammo, i.e., the harder primers, until I switched out the hammer spring.

 

[BRL]

...It was a package deal with a bunch of silver bear .308 ammo which I'm not a fan of...
...the pin struck the primer each time but sounded and felt weak, as if it were only half cocked or something...

...but bear ammo and other steel ammo does have berdan primers that are a little harder to ignite...

Oh, then Silver Bear ammo is steel cased ammo with hard primers?

Didn't know that.

The part about about "...the pin struck the primer each time but sounded and felt weak, as if it were only half cocked or something..." threw me off.

Try a quality brand of brass cased boxer primed .308 ammo and you'll know if it is the steel stuff that's causing your problem.

 

[crockett007]

Don't run steel in a DPMS, they dont like it. Try some brass cases, you'll be happy. Silver Bear is zinc coated steel case. My DPMS 223 will run it for a while, but it is extremely dirty and not highly accurate...Never run uncoated or polymer coated steel cased ammo in a LR.

 

[dh1633pm]

When I got my DPMS LR-308 (which I sold) I had about 200 Wolf 308 hanging out. I sold it to buy more reloading supplies. I had read like above that the rifle didn't like it. Although my FN-FAL (which I sold) did like the stuff.

 

[JW1980]

Thanks for all the comments.

BRL, it doesn't seem to have the "extra shelf" you're talking about. The hammer fell completely no matter how I tried to manipulate it.

I normally wouldnt run silver bear but I'd like to be able to feed my rifles anything in a pinch, so I'll look into a heavier spring. What kind did you get TJohn?

I'm still baffled as to why the rounds that failed the first time through all fired when loaded one by one and charged by hand.

 

[BRL]

...I'm still baffled as to why the rounds that failed the first time through all fired when loaded one by one and charged by hand.

That's not at all unusual with steel cased ammo with hard primers and stock hammer springs.

Maybe the first hit sensitizes the primer even more, so that the seconed hit finally detonates it.

Both of my Mini-30's used to do the same thing with Wolf steel cased 7.62X39 ammo until I ordered two Wolff extra power hammer springs for them.

Wolff makes excellent firearm springs for just about any gun or magazine by the way.

 

[AABEAR]

You might try cleaning it then a little lube take the bolt ALL the way down and clean it very good.

 

[JW1980]

That's too easy BRL, It just took two strikes of the pin. I was hoping for a drawn out confusing explanation. I tend to over think things. Makes perfect sense. Thanks

I broke it down and did a quick wipe and lube before i shot it, but didn't feel the need to be very thorough because it looked pretty clean. I'm sure a good scrub down would help too