Staff Sgt. Elizabeth Sheppard, 28th Security Forces Squadron combat arms instructor, explains the characteristics of the M-249 automatic rifle to Linda Rabe, Rapid City Area Chamber of Commerce president and honorary commander for the 28th Bomb Wing vice commander, during an honorary commander tour at Ellsworth Air Force Base, S.D., June 7, 2013. Attendees participated in a new active shooter training course, combat arms displays and military working dog demonstrations. (U.S. Air Force photo by Master Sgt. John Barton/Released)