So before we get into the Why anyone would want to use the M1D style scope mount on an M1A, I want to get into the How can it mounted or is it possible? I’ve looked up everything I can about both the mount and the rifle and was easily able to find a repro mount and scope. The trouble I’m running into is I can’t find any info on the thread pitch and diameter of the mount screw or the mounting hole on the receiver of the rifle. Does anyone have any idea of if this could potentially work? Thanks!