DPMS LR308 feeding issues

[TFox2112]

I recently purchased an LR 308 and on my first trip out to the range yesterday, I ran one magazine through, no problems. The second magazine would feed two then jam or the bolt would not strip a cartridge from the magazine. On the third magazine, I fired two then the third round failed to feed and the bolt did not lock into battery. The round would not fully chamber nor could I get the round back out of the chamber. We gently Carried the rifle to the house and I left it on the top of the washer, muzzle pointed out the window at a brick wall for the night. This morning I pulled the charging handle and the round popped out like nothing had happened. I will chalk the stuck cartridge up to the ammo(german surplus stuff). Any ideas on the failure to strip rounds from the magazine? I am using P mags. 

[Solus]

Got a question. 

When you say first, second and third magazines, do you mean refills of the same magazine or 3 different magazines?

Taking a guess here since I have no experience with that rifle...

But it seems that after a magazine full, the barrel and and chamber would expand....this does not necessarily mean the chamber would become "bigger" as the metal could expand inward as well as outward.

It could be possible that this expansion could cause the ammo you used to become "oversize" for the chamber, if it was borderline to start.

This is supported by the fact that the stuck round was easily removed after the barrel/chamber had cooled overnight.

If you have the tools, "mic" the dimensions of the ammo and check against the standard dimensions for that cartridge or a known good quality round.

[billt]

Did you clean and lube the rifle, and completely brush and clean the chamber before you went to the range?

[tombogan03884]

90% of all semi auto feed issues are due to magazines.
As to the other issues, what does DPMS recommend for ammo pressures and bullet weights ?
I'll bet money "German surplus" is not on the list.
European military ammo is loaded to function in machine guns (belt fed) it is therefore very hot .
US military ammo is loaded to SAAMI specs.

[TFox2112]

Tombogan, that makes sense on the stuck round. Thanks!

billt, Yes brushed, cleaned and lightly lubed.

solus, three different magazines - #1 Pmag, #2 Pmag, #3 DPMS factory mag. Due to the stuck round, I wasn't able to try the first Pmag again. I do have a mic and I will check the round formerly known as "stuck"
tonight.

Now wondering if the "hot" German stuff was causing the action to cycle too quickly. I will have to get back out and try some other ammo and see. Keep the opinions coming! Thanks, again!

[Sponsor]

[billt]

Try some Winchester White Box 7.62 X 51 MM. That is loaded to pressures semi's can function under. If you handload, try 42 grains of Varget under a 165 Gr. FMJ or similar bullet. That runs my DPMS .308 AP-4 Carbine really well.

[kmitch200]

You can also try some Federal Gold Medal Match or HSM loaded with Bergers if you don't reload.
Buy them when you see them on sale if you don't have a pocket full of extra money. 

My Remmy R-25 (DPMS 308) loves the HSM. It loves the 168 Berger Hybrid handload even more.

[billt]

Any .308 semi should also run good on this stuff.

http://www.midwayusa.com/product/953713383/federal-american-eagle-ammunition-762x51mm-nato-168-grain-open-tip-match

[robert69]

I have a Lr308, heavy barrel, .308.  Love it, shoots great. 10 round 5/8" group @ 100 yds, all day. Dpms test fires the rifles with Federal gold match, Sierra 168 bullets.  This load is pretty warm, but shoots good.
As previously stated, most of these type of problems are magazine related. I only use the DPMS mags, and Have not had the problem.
If you use DPMS 10 rnd mags, only load 9. You can load 10, but 9 works fine, easier on fingers.
Are you using the stock buffer?  I had an issue with a hydraulic buffer, that I could not figure out until I went back to the stock buffer.  That problem has been resolved by replacing the hydraulic buffer. It caused the bolt to short cycle, because the buffer recoil spring was binding on the body of the buffer.
If you are shooting HOT ammo, what happens is the bolt tries to unlock while the pressures are high, which is apparent by looking at the head of the brass, where the mfgs name is stamped. If head swipe is occurring it will look like a file was drawn rotationally across the brass. Pressures will not be the same.
Do NOT shoot steel cased ammo, or surplus ammo. Machine gun ammo, absolutely NOT!
Want to shoot great groups, replace the stock trigger with a Giessele (spelled wrong) national match 2 stage trigger.
The lr308 heavy barrel rifle is amazing how accurate it is with Sierra Match HPBT, and 40 grains of IMR 4895.
Good luck.......

[MikeBjerum]

Since this conversation has already covered cleaning and lubing prior to going to the range and proper first shots, I will go into my "Buy good ammunition" advice:

If you want to try cheap junk a brand new gun is not the place.  Buy good, clean, reliable, manufactured stock until you are sure all is working well.  Once the gun is confirmed operating well, sighted in, and you are comfortable with it you can start playing with odd ammunition and/or reloads.