U.S. Air Force Staff Sgt. Anthony Walker, 354th Communications Squadron quality assurance inspector, fires an M-4 Carbine at the Combat Arms Training Range, July 9, 2013, Eielson Air Force Base, Alaska. Before stepping foot on a live-fire range airmen go through a day of classroom training and practice on an engagement skills trainer. (U.S. Air Force photo by Senior Airman Shawn Nickel/Released)