M16 Firing U.S. Army Staff Sgt. Justin Mark, foreground, fires an M4 rifle at a range near Kabul, Afghanistan, Dec. 8, 2015. Mark is a personal security detail member assigned to the Train, Advise, Assist Command-Air security forces. U.S. Air Force photo by Staff Sgt. Corey Hook SHARE: Download: Full Size (0.5 MB) Tags: Train, KABUL, Advise, Photo Essays, Weapons Training, Assist Command, afghanistan, All images, security forces Credit: Staff Sgt. Corey Hook VIRIN: 151208-F-ZU607-091.JPG Photo Gallery