so what you're telling us is that you've been shrugging hits?

seem's like every gunsmith has at least one of theses... a gun that he never can completly master

As I recall I got semi auto working by shaving down the top of the trigger or something, the trigger was too long so when the cutoff lever hit it, it wouldn't jump off the trigger. Atleast I think that's what it was, I work on a LOT of M4s and encountered a few demon problems. Haven't run into one I couldn't fix yet!
Anyway I remain the M4 gunsmithing champion of Manitoba lol