Well, took my new LR308 build out to the range today to shoot for the first time. Specs are below:
JD Machine Upper & Lower
SI Defense BCG (QPQ coated)
18.5" Criterion Barrel - Chrome Lined - Rifle Length w/ 0.750" gas journal
Centurion Non-Adjustable LP Gas Block (running CMR rail system)
CAR-10 Buffer w/ .308 Carbine Buffer Spring (UBR stock)
In a previous thread I had headspace / bolt jamming issues. This was resolved by swapping out the 7.62 Industries BCG with the SI Defense BCG. The bolt headspaced no problem and everything functions perfectly when cycling by hand (ejection at the 4-5 o'clock position).
So I load 1 round in a 10rd PMAG, fires and ejects no problem, bolt locks back. I continued to do this for about 10 rounds with the same results, but I did start to notice that it looked like some rounds were being ejected forward at the 1-2 o'clock position. I then went ahead and loaded a full 10 rounds. Functioned fine for the first 5 rounds or so and then jammed. The shot case wasn't ejected and was jammed with the bolt trying to chamber a new round. I continued to have this problem intermittently. Sometimes I could go 30 rounds with no problems and other times every couple rounds. I went back to loading 1 round at a time and it ejected fine but some rounds were at the 1-2 o'clock position. Then I had 1 round that apparently did not eject. The bolt locked back, I dropped the mag and the round came falling out with it. I called it a day at this point.
I'm thinking all of this is caused by it being over gassed? Or could it be something else?
If it is over gassed I'm not too sure how to fix it. I don't know of an adjustable gas block that will fit under a CMR. Slash makes a extra heavy CAR10 buffer weight (6.5 ounces vs 5.5 ounces), would that be enough to fix things? Any other options?
Thanks much in advance
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