UPDATE 7/2 - Can a Carbine Require a "Warm Up" to Function Reliably?

[MistWolf]

The leak still need to be fixed, but will not cause failure to eject or a failure to extract. You either have a weak extractor or a weak ejector. Pull the BCG from the rifle, place a spent case in the bolt face and hold it down so the ejector is compressed. Then flick your finger off of it and let it fly. The case should be flung across the room smartly. The only thing I can think of to test the extractor is to put a dummy round in the rifle and cycle the action by hand and watch to see what happens

[SteveL]

At this point I would contact BCM, send them the pic of the BCG you posted, and see about swapping it out. It already appears to have one issue identified. Quit wasting time with it. BCM stands behind their stuff and will take care of you.

[bowman57_2]

It's pretty simple. Remove the extractor and look for the black O-ring around the extractor spring. Sometimes too much extractor tension can cause issues.

I got a new BCM BCG in the mail a few days ago and there was a small black rubber ring in the package, is this for the extractor?

[Storkenheimer]

I got a new BCM BCG in the mail a few days ago and there was a small black rubber ring in the package, is this for the extractor?

Yes, they ship it in the package uninstalled.

The complete BCM KMR rifle i recieved this spring did not have the O ring in the bcg, fwiw.

[sevenhelmet]

Maybe I missed it, but have you tried swapping the BCG for another one? Maybe even put that BCG in another gun and see if the malfunction follows.

My money is on the extractor, but the O-ring will only be a temporary fix, if at all. I'd contact the mfr and see what they recommend.

[arptsprt]

BCM is taking care of me with a replaced/repaired BCG. It is the BCG. I have a spare LMT BCG I tried yesterday and the gun functioned 100% with all ammo for over 100 rounds.

Can't believe it took me so long to diagnose but I am still learning. Now I know if this happens again in the future.

Thanks all for the help.

Maybe I missed it, but have you tried swapping the BCG for another one? Maybe even put that BCG in another gun and see if the malfunction follows.

My money is on the extractor, but the O-ring will only be a temporary fix, if at all. I'd contact the mfr and see what they recommend.

[Cincinnatus]

BCM is taking care of me with a replaced/repaired BCG. It is the BCG. I have a spare LMT BCG I tried yesterday and the gun functioned 100% with all ammo for over 100 rounds.

Can't believe it took me so long to diagnose but I am still learning. Now I know if this happens again in the future.

Thanks all for the help.

Glad to hear you got it sorted out.

[arptsprt]

First, I have already contacted BCM again and I am sure I will hear from them next week...

Got the supposed repaired/replaced BCG back from BCM last week. I could tell it was the same one I sent back. Apparently their repair was insufficient. Had the same malfunctions multiple times again today when I went to the range to test fire.

Again today I once again tried an LMT BCG and another BCM BCG from another BCM rifle and both functioned in the upper just fine for several (over 100) rounds.

What doesn't make sense however, is I tried the problem BCG in my 16" BCM BHF rifle and it ran fine, albeit for only a mag's worth of rounds.

As a reminder, the upper with the problem BCG is a BCM 12.5 KINO about 450 rounds through it at this point.

For those who know better, why would this BCG work with the 16" and not the 12.5?

BCM is taking care of me with a replaced/repaired BCG. It is the BCG. I have a spare LMT BCG I tried yesterday and the gun functioned 100% with all ammo for over 100 rounds.

Can't believe it took me so long to diagnose but I am still learning. Now I know if this happens again in the future.

Thanks all for the help.

[Iraqgunz]

I'm a little lost myself. This doesn't make sense. Take the bolt (only) from the LMT and put it into the BCM carrier. Then do the same with the BCM bolt into the LMT.

First, I have already contacted BCM again and I am sure I will hear from them next week...

Got the supposed repaired/replaced BCG back from BCM last week. I could tell it was the same one I sent back. Apparently their repair was insufficient. Had the same malfunctions multiple times again today when I went to the range to test fire.

Again today I once again tried an LMT BCG and another BCM BCG from another BCM rifle and both functioned in the upper just fine for several (over 100) rounds.

What doesn't make sense however, is I tried the problem BCG in my 16" BCM BHF rifle and it ran fine, albeit for only a mag's worth of rounds.

As a reminder, the upper with the problem BCG is a BCM 12.5 KINO about 450 rounds through it at this point.

For those who know better, why would this BCG work with the 16" and not the 12.5?

[arptsprt]

Ok. I'll try that tomorrow.

The other interesting thing I forgot to point out is the repaired BCM BCG extracted and ejected several rounds just fine with the one round in the mag trick. This was not the case before. The extraction malfunctions all showed up consistently with semi-rapid fire after about the 8-10th round down the pipe. Really odd.

I'm a little lost myself. This doesn't make sense. Take the bolt (only) from the LMT and put it into the BCM carrier. Then do the same with the BCM bolt into the LMT.

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