Quote Originally Posted by grieva View Post
Had a similar problem,was about to give up when I removed the thread protector from the end and could see the threaded portion was bent,with the protector on it looked perfectly straight,carefully straightened the threaded end and now shoots straight and true,the end thread is easily bent.
presumably when it had a silencer attached ?

It's only an M10 fine thread IIRC, so pretty delicate - ~ 8mm core dia with a 5.5mm hole thru it..