AR-15 FTE After Handguard Install


@Johnksg @ValorSolo the CMMG kit is a one piece rig no gas tube/block. I have one on a 4 inch barrel. :+1:t2:

There is also a disclaimer on their website

Rimfire conversion kits are NOT compatible with gas piston equipped AR-15’s. The piston will not allow conversion to fit in the receiver.


Here is my wife’s FN. I can easily slide the bolt home with my finger and it fully engages with no pressure or “stops”…does yours do that?


He has a gas tube so I am guessing that means it is not a piston AR?

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@johnksg they’re called so many different things who knows what the disclaimer means. Gas piston is no gas. Direct impingement is gas. Why have gas in the name of the no gas system?


Honestly, I think it’s something in the BCG. I’m letting it soak awhile then I’ll work on it some more.

When the BCG slides forward, the bolt assembly doesn’t seem to be making that twist or whatever until you bump it in. I believe this should work more freely than it does.
I can let the BCG slam forward, as it would in actual firing, and it goes all the way forward. But then insert a magazine and doesn’t.


It functionsas it should, no gas tube or block requitrred.


@ValorSolo I’d take the gas tube off and see if BCG returns home. Simple test.


Your confusing me brother. A gas piston is gas, and operates a piston to cycle the bolt, such as an AK. A DI system has no piston and runs a gas line that seals directly with the bolt itself without a mechanical interface.


@johnksg I mean gas piston doesn’t inject gas into the BCG. The gas block is chopped off on a piston BCG.


@ValorSolo I am getting a bit confused so if you dont mind backing up a bit?

When you pull the lower and cycle the bolt by hand with your charging handle locked forward it stopped 1/4 inch shy of lockup…correct?

You pulled the gas block and gas line and it is still stopping short?


Yes, that is correct


@ValorSolo now if my above two questions are correct in what your experiences are I would check to make sure that you have your ORIGINAL bolt and the gunsmith did not mix up parts from another project.

Also check that the bolt was assembled properly and has all of its pins.

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It is the original bolt.

I guess a soak helped. I just inserted a mag and hand cycled every round. I can’t go test fire it today, but it would do no good with the gas block and tube off, anyways.


I really appreciate all the help. I’ll post my result after the new block and tube arrive and I can go fire it.


@ValorSolo go shoot it now if you want. Just charge it manually every shot. Then you’re not waiting on the gas tube/block to diagnose the problem.


Just did. Seems fine now.


@ValorSolo what’d the gas tube look like when you took it off? Any damage?


No. It was fine. Or appears to be fine. I’ll still wait for the new parts and install them. I think they are higher quality parts.


My two cents on this mystery … Have you taken the bolt out of the bcg? Any pieces of broken rings, sheared cotter pin making the bolt hang up?


Yes. I’ve inspected everything inside the BCG. Basically a second cleaning after letting things soak seems to have fixed the issue. Just need to do a better job cleaning.