An amphibious assault vehicle crewman with Alpha Company, 2nd Assault Amphibian Battalion, loads simulation rounds into a mounted MK-19 40mm grenade launcher during a live-fire gunnery range at Marine Corps Base Camp Lejeune, North Carolina, July 27, 2016. Marines with the battalion spent the day refining their marksmanship skill as individuals and their ability to work as a crew. - An amphibious assault vehicle crewman with Alpha Company, 2nd Assault Amphibian Battalion, loads simulation rounds into a mounted MK-19 40mm grenade launcher during a live-fire gunnery range at Marine Corps Base Camp Lejeune, North Carolina, July 27, 2016. Marines with the battalion spent the day refining their marksmanship skill as individuals and their ability to work as a crew.