180627-N-UX013-0283 MEDITERRANEAN SEA (June 27, 2018) The guided-missile destroyer USS Jason Dunham (DDG 109) fires its MK-38 25mm machine gun during a pre-action calibration fire exercise. Dunham is operating in the U.S. 6th Fleet area of operations in support of U.S. national security interests in Europe. (U.S. Navy photo by Mass Communication Specialist 3rd Class Jonathan Clay/Released)