The guided-missile destroyer USS Mason fires its 5-inch, 54-caliber lightweight gun during a live-fire exercise with the Chinese army destroyer Harbin in the Gulf of Aden, Aug. 24, 2013. The guided-missile destroyer USS Mason fires its 5-inch, 54-caliber lightweight gun during a live-fire exercise with the Chinese army destroyer Harbin in the Gulf of Aden, Aug. 24, 2013. SHARE: Download: Full Size (1.52 MB) Tags: Photo Essays Credit: VIRIN: 571556-J-HAB81-071.jpg Photo Gallery