Originally Posted by
MQ105
This is a PSA: Ensure your gas block is properly secured! This means, either pinned, or a dimple for a set screw plus thread locker.
I was able to attend a carbine class this past weekend (thank you Jim Carter, et al) and there were two gun problems. One was a low-pro gas block that worked forward enough to make the gun a single-shot. This was near the end of day one, and after several thousand rounds through the gun prior to this class. This gun was purchased fully assembled, not home-grown. (Not that home-built is bad; just FYI)
There was no pin and no set screw dimple. In this case, it was a minor inconvenience because we were on the range. A backup gun allowed the shooter to keep learning, and we fixed the problem that night.
It got several other shooters wondering about their gas block situation. After a quick look at three guns, we found two others in the same condition (no pin/dimple. Neither GB had moved.)
So, how reliable does your rifle/carbine need to be? Just sayin'...