A rotary clip rotation mechanism for an air gun, having a nail for engaging with a nail engagement section provided in the rotary clip and causing rotation of a rotary clip, comprises an L-shaped arm, capable of rotating about an arm shaft, with a muzzle side end opening section formed from a curved surface section; an arm elastic section provided at a position contacting the tip of the curved surface section of the L-shaped arm, a nail support arm provided so as to rotate on a gun rear end side of the L-shaped arm by means of a connecting elastic section, and a nail urged in the direction of the tip end by a nail elastic section provided on a tip of the nail support arm.