marked nsn855-01-506-5750 us property missing attachment screw as new condition $322 at brownells link below M14/M1A Picatinny Scope Mount : M14/M1A TACTICAL SCOPE MOUNT | Brownells $200 shipped M14 Scope Mount, Wire EDM, NSN 5855-01-506-5750 Number one selling M14 scope mount to USG, sold to the USMC for the M39, and to the U.S.Army for std and DMR configurations. MIL STD 1913 with see-through channel for use of issue iron sights. Marked "US Property" and with NSN. Highly advanced metallurgical process. Wire EDM 4140 CM steel manufactured. Double heat treated, as well as M80HT, corrosion resistant 60 HRC surface.