Abstract: A nailer for repeatively driving nails one at a time into material. A safety yoke including an integral safety yoke lever cams against a safety yoke pin in the body of the nailer and actuates a secondary trigger pivotally mounted in a trigger. The secondary trigger actuates a valve plunger in a trigger valve assembly releasing the air over a poppet assembly, causing downward movement of a pneumatic piston assembly carrying a driver blade driving a nail held in a channel guide of a nose into the material. A plurality of tabs on the nose mechanically engage and frictionally lock a nail magazine to the nose. A scroll spring assembly affixes to the nose and biases a pusher in an adjacent track of the magazine towards the nose. A safety yoke detent biased away from the nose moves forwardly into a detent notch in the safety yoke by the pusher when the supply of nails remaining in the magazine reaches a predetermined number.