DPMS LR-308 failure to feed/cycle completely

CROWS 0311

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Joined
Dec 16, 2012
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36
Location
Madison, Wisconsin
Hey, Shooters.

Looking for a bit of advice outside the internet warriors in other forums and airsoft commandos. I've built a DPMS LR-308 from scratch over the last few months, and took it to the range today hoping to pop the sewwtest cherry I've ever had the experience of witnessing. Dreams were dashed when I realised I had in my hands a $1,500 bolt action rifle.

I can't give you a particular build, as it is my own, but here are the specs I can give you:

-DPMS Panther 308 lower reciever (standard DPMS 308 parts kit interior)
-PRS Stock, mil spec tube, standard DPMS tube/spring
-Standard DPMS BCG/charging handle
-NEMO .308 Nitride finish 20" barrel, JP recoil eliminator compensator
-SYRAC ORDNANCE adjustable gas block, rifle length free float handguard (PRI Delta Carbon Fiber yadda yadda)

Now I did test fire it after completing the rifle, in an indoor range, and it fired 4 rounds flawlessly. The next day I put my optics on it, and settled in to BZO, however, started having serious issues.

Issue 1-Failure to feed. The rifle would fire one round, but would not properly feed in a second. I observed this myself, having someone else fire as I watched the action from the Ejection Port side.

Issue 2-General Stiffness. At some points, the charging handle would flat out require me to place the butt in my sternum and use both hands to rack a round.

Ok, now to eliminate some potential questions. Yes, I adjusted the gas block in an attempt to fix the feeding/cycling issues. After adjusting completely inwards on the pin(less gas), it was clearly visible the BCG wasnt even making it back halfway to the rear of the next round. This also eliminates questions about failure to eject, as this was the only time it happened for obvious reasons. When the gas block was adjusted all the way out(more gas), the head of the Bolt could still be seen during cycling, and could not catch the next round.

I have standard DPMS steel 20rd mags, which I've now seen others have posted issues on. This, however, is not a valid point in this case as I test fired it 4 straight with no issues with the same magazines. Another thing I thought of was possibly the temperature. It was about 28 degrees out, a good day for a Wisconsin lad such as myself, but maybe not for my rifle. I also utilized a great deal of oil on the BCG and inside the upper receiver (I didn't drown it, spent 8 years Marine Infantry), but not enough to hinder the weapon.

The rounds had no scarring on them from rifling, eliminating a short throat on the rifle as a culprit. I was using Federal 168 grain .308 rounds. I have read these systems don't much care for below 175-180grain rounds, but with an adjustable gas block AND successful test fire, again, I'm at a loss.


Any ideas would be appreciated, Dumb it down for me if you can, I'm definitely not ARtarded, but I will most likely be reading inbetween pulls off my beer and scratching my head. Thanks in advance, guys/gals. I'm not sure where to go with this.
 
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Is your bolt/carrier lubricated? Did you check the buffer/spring/detent? Did you pull the BCG out of the upper and inspect the upper and carrier? If you jam your finger in the chamber and blow down the muzzle can you feel air coming out of the end of the gas tube in the receiver?
 
id make sure the gas block is lined up with the port. pushing the block up against the shoulder of the barrel is often too far back.<br /><br />that, and lubrication. get the carrier wet w lube outside and inside along w the bolt.<br /><br />Make sure your gas tube is long enough, theres a bastard rifle length tube thats about 3/16" longer for some 308 barrels.
 
Thanks, guys. That's all good stuff, I'll try it all out when I get the chance. Knew this would be a good place to ask!

Appreciate the advice, now I at least have a few directions to go.
 
I know this is an old topic but I came across it and found that the answers given were not to my liking so I thought i would expound on this issue and relating causes.
For ar-10 /ar-15 variants - failure to fires and or non rechambering of ammo .
These are all possible issues to check
-lose gas block
-Improper positioning of gas block over port on barrel
- Wrong buffer spring ie( rifle buffer spring in carbine stock)
-wrong buffer
- Improperly headspaced bolt
- Missing spring in trigger group
-wrong ammo (7.62 in 308winchesrer chambering )
-Bad ammo (reloads) -sometimes factory
-Wrong bolt for chambering
-broken extractor
 
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