Ingame the M320 operates as a semi automatic, but if you look at the rifle and its reload animation you can is its a action bolt weapon. The bolt is even "locked" in place at the end of the animation.
You would fire, absorb the recoil, then move your trigger arm to operate the action bolt ejecting the casing and moving another into the chamber from the mag.
This would obviously take allot more time than it currently dose ingame and it would not be confused with a semi.
Look at the picture and ask yourself if that looks recoil operated? Were would the "power" for pushing the bolt back even come from?
If the A3 weapon is based on the Cheytac its wiki page also states its a bolt action.
(Info box on the left at the bottom. At the line "Action: Bolt action.")