Sgt. Richard Mccain, training chief, Reserve Support Unit, gives students from the Naval ROTC program a crash course in using the M16A4 service rifle during indoor simulated marksmanship training at Camp Upshur on Saturday. The students also completed the obstacle course before the end of the day. - Sgt. Richard Mccain, training chief, Reserve Support Unit, gives students from the Naval ROTC program a crash course in using the M16A4 service rifle during indoor simulated marksmanship training at Camp Upshur on Saturday. The students also completed the obstacle course before the end of the day.