Machine Gun Exercise A sailor fires a .50-caliber machine gun during a live-fire exercise on Joint Base Lewis McChord, Wash., Oct. 21, 2015. The sailors, who conducted gun qualifications on the base, are assigned to the USS Nimitz. U.S. Navy photo by Petty Officer 3rd Class Lauren K. Jennings SHARE: Download: Full Size (1.85 MB) Credit: Petty Officer 3rd Class Lauren K. Jennings VIRIN: 151021-D-HV319-481.JPG Photo Gallery