I’m about to rebarrel a carbine upper and I’m wondering if I could reuse the gas tube, or should get a brand new one while I’m at it?
I replace them every 5-10K rounds. When ever I sear the end of if wear down so that it’s the same size as the rest of the tube. A new one has a bulb like end which is larger than the tube itself.
The gas key wears too…
any erosion inside the tube? or just the frictional wear from the gas key really?
I’ve had quality chrome lined keys go beyond 40K rounds. That was with a Colt carrier key over a few year period. I have no doubt a BCM key would do it too.
A good idea for re-barreling is to replace the gas tube and bolt as well.
Not a bad idea but there’s a very easy way to check it:
If a new gas tube or the gas tube alignment gauge fits snugly into the carrier key then your carrier key is GTG.