Keywords: US Navy 120128-N-ZW558-002 The MK-45 5-inch.54-caliber lightweight gun fires aboard the Arleigh Burke-class guided-missile destroyer USS Porter (D.jpg en ATLANTIC OCEAN Jan 28 2012 The MK-45 5-inch/ 54-caliber lightweight gun fires aboard the Arleigh Burke-class guided-missile destroyer USS Porter DDG 78 during a live-fire exercise Porter is part of the Enterprise Carrier Strike Group which is underway conducting a composite training unit exercise U S Navy photo by Information System Technician Seaman Nathan A Carroll/Released 2012-01-28 120128-N-ZW558-002 Navy http //www navy mil/view_image asp id 114423 U S Navy photo by Information System Technician Seaman Nathan A Carroll PD-USGov-Military-Navy USS Porter DDG-78 5 /54 caliber Mark 45 gun firing |