At the U.S. Army’s Sniper School at Fort Benning in Georgia, students undergo some of the most grueling training the force offers.

Sniper school is one of the hardest schools in the military, not physically, but mentally,” Staff Sgt. Brian Moran, one of the 11 instructors who oversees the training, told the Army News Service.

Army snipers face demanding missions and often operate with little or no support, and the training at Fort Benning tests their ability to work in isolation and under pressure.