A rack of propane and oxygen powered guns hang at Cannon Air Force Base, N.M., Sep. 9, 2019. Currently, the training rifles are powered by propane and oxygen that is routed to the weapons through tubes into a bulky bag. The combat training element team are working out routing this power into the gun itself, in locations such as the magazine, to provide more mobility for the teams utilizing the weapons. (U.S. Air Force photo by Senior Airman Gage Daniel)