I’ve seen references to an M1903A1 rifle. I’ve looked around at a bunch of gun shows, and I have not found a rifle marked “M1903A1.” How does that variant differ from a standard M1903 rifle?

There is some controversy today about exactly what constitutes a M1903A1 rifle. Apparently, the military considered any Springfield rifle fitted, even retrofitted, with a Type C stock as a M1903A1.