Marines with 2nd Battalion, 2nd Marine Regiment learn how to make adjustments on the 61mm mortar system at a live-fire range aboard Camp Lejeune, N.C., June 25, 2015. The exercise allowed Marines new to the unit to gain knowledge and experience with both 61mm and 80 mm mortal systems. (U.S. Marine Corps photo by Cpl. Michael Dye/Released) - Marines with 2nd Battalion, 2nd Marine Regiment learn how to make adjustments on the 61mm mortar system at a live-fire range aboard Camp Lejeune, N.C., June 25, 2015. The exercise allowed Marines new to the unit to gain knowledge and experience with both 61mm and 80 mm mortal systems. (U.S. Marine Corps photo by Cpl. Michael Dye/Released)