BCM Gas Block Problem

[freebug]

I bought a LPG from BCM along with their light weight barrel (mid-length gas system) but its been sitting in the box until I finally got around to assembling another build.

The issue is the gas block not seating against the barrel properly. The barrel has a divot for the set screw in the gas block but when I tighten it down, it causes the gas block to back off the back of the barrel (where all my other builds sit tight).

Has anyone else used the BCM light weight barrel + BCM LPG and have this problem? I'm emailing BCM as well to see if its normal or not.

[G21Shooter]

Only one way to tell, shoot the rifle and see if it functions like that.

[JDay]

Contact BCM, if there's anything wrong with it they'll make it right.

[perpetual otter]

That's weird.

[Darklyte27]

Ohh that gap.. interesting...

[ott1]

The divot might be slightly off on the barrel.

[beenawhile]

There needs to be room for the hand guard end cap ( not sure if that's the technical term) if you were to use a drop in rail or regular hand guard.

[TheDigitalPicasso]

I have the same BCM LW 14.5" barrel and a BCM .750 low pro gas block and I have the same gap. I've already put 400 rounds through it without any problems. Just make sure the gas block is aligned with the gas port and use some 1200 degree lock tight for the bottom screws.

[TheDigitalPicasso]

There needs to be room for the hand guard end cap ( not sure if that's the technical term) if you were to use a drop in rail or regular hand guard.

Exactly what he said. If you were to put that round plate and a delta ring on the other end you can drop in the rails.

[freebug]

Thanks guys. I forgot about the hand guard end cap. That's what it's there for.

The funny thing on all the other rifles I have with LPGB, they don't leave a gap for that. Maybe inside the LPGB, the vent is enlarged so there's room to move around.

Worries are over. Now to the range on Sunday to test it out.

[dichter]

Since BCM test fire all their uppers, I doubt that's a problem in the first place. They should have spotted it.

Sounds like you are good to go.


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[ar15barrels]

I bought a LPG from BCM along with their light weight barrel (mid-length gas system) but its been sitting in the box until I finally got around to assembling another build.

The issue is the gas block not seating against the barrel properly. The barrel has a divot for the set screw in the gas block but when I tighten it down, it causes the gas block to back off the back of the barrel (where all my other builds sit tight).

Has anyone else used the BCM light weight barrel + BCM LPG and have this problem? I'm emailing BCM as well to see if its normal or not.

it is normal.
The gas port is properly located on the barrel so that if you installed a handguard cap behind the gas block, that the gas port in the gas block would perfectly align with the gas port in the barrel.
Since you do NOT have a handguard cap, you will have a gap there.

[G21Shooter]

Thanks guys. I forgot about the hand guard end cap. That's what it's there for.

The funny thing on all the other rifles I have with LPGB, they don't leave a gap for that. Maybe inside the LPGB, the vent is enlarged so there's room to move around.

Worries are over. Now to the range on Sunday to test it out.

Yeah the gas hole in the gas block is much larger than the gas port in the barrel so it leave some room for error.

Make sure to put some Rocksett on the gas block set screws, you don't wan't those coming loose.

[jpm804]

Now let's see a full picture with that Fortis rail on it...

[freebug]

Here you go. I'm no Stickman, but here's a couple of shots.

BCM 14.5 5.56



300BLK 16 CMMG 1:8