Has anyone ever tried to convert a small pin upper by drilling out the hole to the large pin diameter? I know the holes are are offset but have a friend who is a machinist and it seems like the trick would be to devise a holding fixture to line everything up.

I picked up a small pin Colt flattop upper to put on my large pin Colt service rifle lower and am tired of messing with the offset pin adapter.


Too close for irons, switching to scope...