To be really honest and frank, unless you have a 7.62mm barrel to be getting on with you wont really have any idea about the re-welded geometry of your very hybrid gun. Only when you get the barrel can you practically set up the gun properly as opposed to theorising. But all isn't lost. You can carefully stone the locking surface of the locking shoulder providing you don't tell anyone that we suggested it. The breech block stops weren't modified during the conversion process