I'll assume you use bore guides religously when cleaning your firearms. Over cleaning(hard rods rubbing the bore at either the muzzle or breech) has probably done more harm in military issue firearms than any ammunition. Have you ever seen a .22 riimfire pistol with a shotout barrel? Neither have I but, is a good exampe of using only lead for bullets. On the other hand a build up of copper can cause accuracy problems but, nothing 7.62 or other chemicals can't handle.
I'm actually of the opinion lead bullets swag the bore with each passing through?
I think all gun lovers have your afflixtion with clean guns.
Steve