Precision CNC machined to exact Mil. Std. 1913 specification rail dimensions from a single billet of steel. They match the receiver contour, ensuring straight and true alignment. Scallops on the side will not interfere with loading or extraction. Remington 700 and Win 70 bases include an integral recoil lug machined into the bottom. This provides a precise fit, prevents movement of the base and eliminates recoil stress on mounting screws.