U.S. Marine Corps Lance Cpl. Christopher Semenske, a field artillery cannoneer with Battery G, 2nd Battalion, 11th Marine Regiment, swabs the breach on an M777 Lightweight 155mm Howitzer during Exercise DESERT SCIMITAR aboard Marine Corps Air-Ground Combat Center 29 Palms May 2, 2013. Exercise DESERT SCIMITAR was conducted to allow 1st Marine Division to sustain their ability to plan and execute command and control functions in both offensive and defensive scenarios. (U.S. Marine Corps photo by Lance Cpl. Sean Searfus, 1st Marine Division/Released)