If you just bought it, and just took it to the range,
YOU DON'T NEED TO TAKE IT OUT in the first place.
Lock the bolt/operating rod to the rear. Turn the rifle upside down and back again. You should hear the gas piston go back and forth.
It that's the case leave it alone and pay attention the SA's instructions.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071