Poor precision in machining. - Faxon Firearms Duty Series 9mm Luger, Glock 48 Non-Threaded Pistol Barrel

The breach block does not fit into the factory Glock slide without modification. The threads on the end of the barrel are not true to the barrel. I have a compensator that spins freely onto my G43X barrel, but when I try to put it on this barrel it goes on about half a turn and jams. There is a rub mark on the barrel where the compensator is binding because the barrel threads are pointing off in a wonky direction.