I didn’t know they used shot line adapters. When I saw the photo I thought he was using a suppressor.
PACIFIC OCEAN (March 24, 2008) Gunner’s Mate 3rd Class Aan J. Doscher, assigned to the dock landing ship USS Harpers Ferry (LSD 49), fires an M-14 with a shot line adapter toward the Military Sealift Command combat stores ship USNS San Jose (T-AFS 7) during a refueling-at-sea. Harpers Ferry is assigned to the Essex Expeditionary Strike Group. U.S. Navy photo by Mass Communication Specialist 2nd Class Joshua J. Wahl (Released)
Full sized photo here.