I've seen the O-rings cause this issue. They are only needed on pistol length and CAR length gas guns. Helps with many piston ARs too.
Printable View
I've seen the O-rings cause this issue. They are only needed on pistol length and CAR length gas guns. Helps with many piston ARs too.
There was reciently a thread on TOS about cold weather and 0-ring use. It was causing problems as well and was also a BCM BCG. After seeing this issue I noticed that AAC is using a "new" green o-ring in there uppers that RSilvers stated was supposed to have been tested down to -60.
Not sure that is the problem, and I am in no way an ARsmith. Just passing on some hopefully relevant info.