Cpl. Caleb O’Herien, indoor simulated marksmanship trainer instructor, Reserve Support Unit, explains to the 557 Lorne Scots Royal Canadian Army Cadets how to work their weapon before the start of the indoor simulated marksmanship trainer at Camp Upshur aboard Marine Corps Base Quantico on March 13, 2014. More than 40 cadets participated in the simulation. - Cpl. Caleb O’Herien, indoor simulated marksmanship trainer instructor, Reserve Support Unit, explains to the 557 Lorne Scots Royal Canadian Army Cadets how to work their weapon before the start of the indoor simulated marksmanship trainer at Camp Upshur aboard Marine Corps Base Quantico on March 13, 2014. More than 40 cadets participated in the simulation.