M4 Focus U.S. Marine Corps Staff Sgt. Dustin Dixon fires his M4 service rifle at simulated targets during a tactical exercise to recover aircraft and personnel at an undisclosed location in Southwest Asia, Dec. 28, 2015. Dixon is a platoon sergeant assigned to Charlie Company, 1st Battalion, 7th Marine Regiment, Special Purpose Marine Air-Ground Task Force-Crisis Response Central Command. U.S. Marine Corps photo by Lance Cpl. Clarence Leake SHARE: Download: Full Size (0.45 MB) Credit: Lance Cpl. Clarence Leake VIRIN: 151228-M-NF116-092.JPG Photo Gallery