AT-4 BACKBLAST U.S. Navy Seabees fire an AT-4 rocket launcher at a target during a live-fire training course on Camp Shelby, Miss., May 31, 2008. The AT-4 is a shoulder-launched, lightweight anti-armor weapon. The Seabees are assigned to Naval Mobile Construction Battalion 7. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 186816-P-DVG18-963.jpg Photo Gallery