andy t
03-07-13, 15:45
Here is the timeline:
Upper: BCM BFH 16" upper with mid gas. BCM Bolt, LMT semi carrier
Rifle had about 600 rounds fired through before with no cleaning.
Lower: Pre-94 Colt with OEM parts. H Buffer. Has BAD installed
The rifle has no prior issues.
No lubrication was done prior to firing.
Magazines: Two different USGI aluminum.
Ammo: Wolf .223
At the range:
Successfully fired about 130 rounds. Then when the rifle was locked open. I inserted a partially loaded 30 round magazine. Press BAD. The bolt goes forward, but stops with about 1/4 way left to go.
The top round is partially pulled from the mag lips.
Lock the bolt to the rear. Repeat with a different magazine, same result.
At this point I did a quick disassembly / inspection. The BCG was rather dry and a bit dirty. I did quick cleaning and lubed the bolt, carrier, and carrier rails.
After reassembly, the rifle functioned fine.
I also measured the action spring - it was about 10.5"
I am curious as to what could potentially cause this malfunction?
Thanks!
Upper: BCM BFH 16" upper with mid gas. BCM Bolt, LMT semi carrier
Rifle had about 600 rounds fired through before with no cleaning.
Lower: Pre-94 Colt with OEM parts. H Buffer. Has BAD installed
The rifle has no prior issues.
No lubrication was done prior to firing.
Magazines: Two different USGI aluminum.
Ammo: Wolf .223
At the range:
Successfully fired about 130 rounds. Then when the rifle was locked open. I inserted a partially loaded 30 round magazine. Press BAD. The bolt goes forward, but stops with about 1/4 way left to go.
The top round is partially pulled from the mag lips.
Lock the bolt to the rear. Repeat with a different magazine, same result.
At this point I did a quick disassembly / inspection. The BCG was rather dry and a bit dirty. I did quick cleaning and lubed the bolt, carrier, and carrier rails.
After reassembly, the rifle functioned fine.
I also measured the action spring - it was about 10.5"
I am curious as to what could potentially cause this malfunction?
Thanks!