This Remington manufactured open (rear) sight screw is for the model 510 Targetmaster bolt action rimfire rifle and is in very good condition with light wear.  (file photo)

Note: Remington model 510 Targetmaster rifles with the following date codes (month and year of manufacture) have been observed with this part: PH (June 1939), LJ (February 1940), PJ (June 1940), EK (October 1941), LL (February 1942), CL (April 1942), OL (July 1942), ESS (Oct. 1947), & AC (March 1956).