Lance Cpl. Xavier Castro, a rifleman with 1st Battalion, 8th Marine Regiment, fires his M203 rifle-mounted grenade launcher during a M203 qualification aboard Marine Corps Base Camp Lejeune, North Carolina, April 5, 2015. The M203 grenade launcher fires various types of 40 mm ammunition, ranging from high explosive to ground marking rounds. - Lance Cpl. Xavier Castro, a rifleman with 1st Battalion, 8th Marine Regiment, fires his M203 rifle-mounted grenade launcher during a M203 qualification aboard Marine Corps Base Camp Lejeune, North Carolina, April 5, 2015. The M203 grenade launcher fires various types of 40 mm ammunition, ranging from high explosive to ground marking rounds.