Around the Corps U.S. Marines with 15th Marine Expeditionary Unit fire Mark 19 40 mm grenade machine guns during a theater amphibious combat rehearsal (TACR) in the U.S. 5th Fleet area of operations. TACR integrates U.S. Navy and Marine Corps assets to practice and rehearse a range of critical combat-related capabilities available to U.S. Central Command, both afloat and ashore, to promote stability and security in the region. (U.S. Marine Corps video by Staff Sgt. Kassie McDole) | Marine Forces