An Airman assigned to Luke Air Force Base fires an M4 Carbine while wearing a gas mask as a requirement for the M4 qualification course on June 19, 2019, at Maricopa County Sheriff’s Office Firing Range in Buckeye, Ariz. The two-day course instructs Airmen on shooting procedures such as how to clear the weapon, assess a malfunction or stoppage, unload and reload. (U.S. Air Force photo by Airman 1st Class Leala Marquez)