Rifle: (all new parts, I built the lower, but the upper was built by someone with whom I only had email communications)
- Armalite upper (without M4 feedramps) w midlenght barrel (with M4 feedramps)
- No name B/BC group (rough finish type, no stamping, possibly DPMS or ASA)
- Bushy lower with DPMS LPK
- RRA std buffer & mainspring
Ammo:
- only American Eagle 55 gr FMJ, so far.
- Half of it was stamped "Federal" (that's normal), while the other half had the NATO symbol and LC 04 (Lake City), with red sealant around primer
I've shot a total of about 250 rds and in the last 25 (the NATO LC04 casing), i experience about 3 FTF.
The primers were struck, but too softly. When putting back the round in the rifle a second time it finally went off. Bolt locks back on last round everytime.
Do i just need to relax & carry-on w the break-in ?
Here's two possible issues I can think of:
1) The no-name B/BC was checked, staked & extractor system replaced by a pro armorer... Armalite's official retailer in Canada, in fact. He and his friend (the guy who assembled my upper), said that there was a lot of internal friction between that BC & the upper, but I just needed to shoot a few hundred rds to see if it would work out. So I put alot of CLP & fired away.
Since the bolt is new and could be slightly out-of-spec, can it be sometimes not fully locking on the lugs, thus making more distance between the bolt face and primer ?
2) is it known whether Am Eagle 55 gr, especially the NATO stamped stuff, have very hard primers ?
Thanks