U.S. Marines with 3rd Battalion, 14th Marines, 4th Marine Division, insert a round into a M777-A2 howitzer during an indirect fire exercise on Camp Lejeune, N.C., March 30, 2016. The exercise was designed to integrate, build relations with 10th Marine Regiment and conduct firing drills on unfamiliar terrain. (U.S. Marine Corps photo by Lance Cpl. Melanye E. Martinez, 2D MARDIV Combat Camera/Released)

U.S. Marine Corps Cpl. Neil Murphy, a field artillery cannoneer with 3rd Battalion, 14th Marines, 4th Marine Division, gives the command to fire a M777-A2 howitzer during an indirect fire exercise on Camp Lejeune, N.C., March 30, 2016. The exercise was designed to integrate, build relations with 10th Marine Regiment and conduct firing drills on unfamiliar terrain. (U.S. Marine Corps photo by Lance Cpl. Melanye E. Martinez, 2D MARDIV Combat Camera/Released)

U.S. Marines with 3rd Battalion, 14th Marines, 4th Marine Division, set up M777-A2 howitzers for an indirect fire exercise on Camp Lejeune, N.C., March 31, 2016. The exercise was designed to integrate, build relations with 10th Marine Regiment and conduct firing drills on unfamiliar terrain. (U.S. Marine Corps photo by Lance Cpl. Melanye E. Martinez, 2D MARDIV Combat Camera/Released)

U.S. Marine Corps Lance Cpl. Jaime Toyos, a field artillery cannoneer with 3rd Battalion, 14th Marines, 4th Marine Division, prepares to insert gun powder into a M777-A2 howitzer during an indirect fire exercise on Camp Lejeune, N.C., March 30, 2016. The exercise was designed to integrate, build relations with 10th Marine Regiment and conduct firing drills on unfamiliar terrain. (U.S. Marine Corps photo by Lance Cpl. Melanye E. Martinez, 2D MARDIV Combat Camera/Released)