Failure to chamber a round from bolt lock

[andy t]

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!

[Arctic1]

Lack of lube probably.

[CrazyFingers]

Just personal experience and not necessarily applicable...
I've noticed the steel casings of Wolf seem to have noticeably more friction in a USGI mag than brass. When I had to hand unload a few loaded USGI mags, it was fairly difficult to get the Wolf rounds out. Couple this with a dirty, unlubed BCG, and I can see how there might be enough friction to prevent the rifle from going fully into battery.
Just my $0.02, and worth every penny.

[Thump_rrr]

Lack of lube probably.

^^^^We have a winner.

[Iraqgunz]

If the carrier isn't wet, then you are wrong.

[Eric D.]

The gas rings, bolt tail, and carrier bore are the first places to go dry. When they do the bolt can bind. Squirt some lube into the vent holes and you're back in business.

[Sentaruu]

Lack of lube probably.

friction is the enemy.

[andy t]

Thanks! An old lesson about lubrication re-learned.

[sinlessorrow]

Wolf ammo has a lot more friction in aluminum GI mags than brass.
I have experienced this even with well lubed guns. I like to put some lube on a rag and wipe the cases down to clean them up and remove that sticky white powdery crap on Wolf ammo.

[ramairthree]

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!

Easy fix.
Always have a small bottle of lube with your kit.
Always lube before you are going to shoot or going into a situation where you may have to shoot.
Should be good to go.

[madryan]

I've done a couple of builds with that exact barrel and you shouldn't need an H-Buffer.

Just sayin...

[eodinert]

Underpowered Wolf + Dry BCG = No workie

[Blak1508]

Id also get rid of the magpul BAD lever... I know they cause issues on some rifles and bad habits across the board. I took a course and had the BAD lever installed and was told to take it off.. YMMV I dont think your issue is related to one but just a thought.