Tech. Sgt. Eric Thomas, an instructor with the 343rd Training Squadron, prepares M-67 training grenades June 18 at Camp Bullis, Texas. (U.S. Air Force photo/Robbin Cresswell)

A student with the Security Forces Basic Officers' Course (left) and an instructor with the 343rd Training Squadron take cover after the student throws a live grenade June 18 at Camp Bullis, Texas. (U.S. Air Force photo/Robbin Cresswell)

A row of M-67 training grenades sit on a bay ledge June 18 at Camp Bullis, Texas. Students with the Security Force Basic Officers' Course practice throwing the trainer grenades before moving on to live ordnance. (U.S. Air Force photo/Robbin Cresswell)

Lt. Col. Francisco Orellana, a student in the Security Forces Basic Officers' Course, prepares to throw an M-67 simulator grenade as instructor Tech. Sgt. Kerissa Rivas observes June 18 at Camp Bullis, Texas. The course teaches students to be a security forces flight commander and covers basic career field knowledge and history, law enforcement functions, security operations and air base defense. Sergeant Rivas is with the 343rd Training Squadron. (U.S. Air Force photo/Robbin Cresswell)

Staff Sgt. John Plemons gives a lecture on employing the M-67 hand grenade June 18 at Camp Bullis, Texas. The Security Forces Basic Officers' Course students practice throwing simulated grenades before moving on to live ordnance. Sergeant Plemons is an instructor with the 343rd Training Squadron. (U.S. Air Force photo/Robbin Cresswell)