This Remington manufactured early variation rear receiver insert has the two "threaded" holes on the underside designed to attach the early variation two hole magazine lock using two machined screws. This rear receiver insert is for the early model 511 Scoremaster bolt action rimfire rifle and is in very good condition with light wear. (file photo)

Note: Firearms with the following date codes have been observed with this part: AH (March 1939), KH (May 1939), PH (June 1939), DH (September 1939), LK (February 1941), CK (April 1941), EK (October 1941), RK (November 1941) & ATT (March 1948)