Rattling gas tube in upper...

[Mr. Goodtimes]

I've got a BCM 16in Midlength with Larue Tactical 11in rail. I noticed the other day after I got back from the range that there was a rattle in the upper receiver. After some trouble shooting I narrowed it down to being the gas tube. Apparently it's rattling around in the upper reciever, however, it only does this when the bolt is locked back.

My question is.. Is this normal?

[Robb Jensen]

I've got a BCM 16in Midlength with Larue Tactical 11in rail. I noticed the other day after I got back from the range that there was a rattle in the upper receiver. After some trouble shooting I narrowed it down to being the gas tube. Apparently it's rattling around in the upper reciever, however, it only does this when the bolt is locked back.

My question is.. Is this normal?

On some guns it'll rattle on other it won't. It doesn't hurt anything unless the gas tube is bent where it engages the gas key.

[GreyOps]

Normal, and preferable. As movement of the gas tube (in the receiver) will prevent the tube from interfering with the proper movement of the carrier and increase consistency.

[Mr. Goodtimes]

Thanks for the clarification. It actually doesn't move hardly any at all, however a jaring motion to the gun will cause it to make a metallic sound. Jaring motions to the gun, especially the rail seem to have a sort of tuning fork effect on the gas tube/upper receiver.

[Quib]

http://http://www.m4carbine.net/showthread.php?t=72614

[opmike]

My BCM has a little rattle. No worries...

[Solitude]

That's a good thing. Means that your bbl nut is not pressing on either side of the tube (it is properly indexed). This allows the aft end of the tube to more easily slip into the gas key and helps prevent uneven wear on both the key and tube.

[Iraqgunz]

I think this has been sufficiently addressed.