A U.S. Airman assigned to the 20th Equipment Maintenance Squadron armament maintenance flight carries an inspected M61A1 Vulcan 20 mm rotary cannon ammunition drum at Shaw Air Force Base, S.C., Aug. 2, 2018. The drum is the mechanism that allows the Vulcan to hold approximately 400 rounds. (U.S. Air Force photo by Senior Airman Christopher Maldonado)