Leupold STD Springfield 1903 A3 1-pc Mount, Black Finish Versatile, and available for many different rifles The forward part of the base accepts a dovetail ring, locking it solidly into position; The rear ring is secured by windage adjustment screws Durable machined and forged steel construction Long Range STD mounts provide a 15-MOA slope of built-in elevation compensating for bullet drop at extreme ranges