U.S. Marine Corps Pvt. James Jamison, a machine gunner with the 1st Battalion, 23rd Marine Regiment, fires an M240B machine gun during a live-fire range at Fort Polk, La., June 2, 2014.
Marines took part in numerous live-fire ranges, which culminated in a platoon size attack as a part of the Marine Forces Reserve unit's annual training. (DoD photo by Cpl. John M. McCall, U.S. Marine Corps/Released). Original public domain image from Flickr