Maj. Scott Howe, the commander of the operations flight assigned to the 28th Civil Engineer Squadron, assembles an M4 during the Prime Base Engineer Emergency Force (BEEF) challenge at Ellsworth Air Force Base, S.D., Aug. 17, 2017. During the M4 relay, an Airman runs down to field-strip an M4, then tags another Airman who then runs back to the M4 to reassemble and function check the weapon. (U.S. Air Force photo by Airman 1st Class Donald C. Knechtel)