I have a 1953 pre model K-22 and have been having difficulty getting the rear sight over to the right, it gets to about where the rear sight blade is centered and stops. I took it upon myself to remove the screw and figure out why it wants to stop, fortunately I did not loose the small slotted capture nut while doing this impromptu "gunsmithing" at the range on the bench. I reassembled the screw into the rear blade and managed to keep it off to the right while retaining the spring and ball. I decided to give the brain-trust a shot before using my trusted Smith guru and generally wasting his time.
