When did they stop producing the flat sight screws as opposed to the rounded ones? My 1956 Combat Magnum has the flat screw and my 1959 M19-0 has the rounded one. Thanks, Big Larry
• Target sight update for all revolvers May 29, 1958 change order: change from 6 to 12 clicks for one complete revolution. Windage screw: Add .286 Radius crown and relocate plunger hole, Elevation nut: Add .286 Radius crown and relocate plunger hole. Reason: finer adjustment.