Assume it was tightened to what it is spposed to be, wouldn't the pin on the barrel extension be crushed or the first few threads where the pin sits be busted then??

Quote Originally Posted by BPTactical View Post
Plenty of "Yikes" in that but I would not say it is non-repairable. Once he has the forend off take a look at the barrel/barrel nut relationship. It is non concentric and then his comments about the gas port alignment set off the lightbulb.
The builder did not make sure the extension pin was fully seated in its slot before tightening the barrel nut. More than likely the pin is sitting on the face of the receiver ring and the builder tightened the barrel nut. This caused the barrel to "cock" relative to the receiver and causing all sorts of maladies.
Quite fixable unless the receiver is seriously damaged.