I have a PSA 20" flat top with their carry handle. I had it sighted in at 25yds during the winter. When I took it out this summer it was pretty off. Anyway, that is an easy fix. I have a Knights Armament rail but haven't added anything to it because I enjoy the lightweight and historic look. Was in the Air Force when they actually ran and this was the first firearm I ever shot. Seem to recall the rifles being dark green.