A fastening tool comprising: a housing having an engine receiving portion; a drive engine located in the engine receiving portion, the drive engine comprising a cylinder and a piston reciprocally mounted within the cylinder, the piston comprising a driver configured to move along a drive axis to drive a fastener during a drive stroke; a nose assembly carried by the housing, the nose assembly comprising a fastener drive track configured to receive the driver, and a movable portion biased in a retracted position towards the housing and movable to an extended position away from the housing; a magazine assembly constructed and arranged to feed successively leading fasteners from a supply of fasteners contained therein into the drive track; and an actuation device configured to actuate the drive engine to initiate the drive stroke, the actuation device comprising a contact trip assembly operatively connected to the movable portion of the nose assembly, the contact trip assembly comprising a lower contact arm connected to the movable portion of the nose assembly biased in the retracted position and movable to the extended position with the moveable portion of the nose assembly, and an upper contact arm operatively connected to the lower contact arm; and a trigger assembly comprising a trigger, a trigger arm pivotally supported by the trigger and configured to interact with the upper contact arm, and a dry fire lockout configured to prevent initiation of the drive stroke when a predetermined number of fasteners remain in the magazine assembly and characterized in that the dry fire lock out is configured to prevent initiation of the drive stroke by disengaging the upper contact arm from the lower contact arm; further wherein the magazine assembly comprises a pusher, and wherein the dry fire lockout includes a protrusion of the pusher extending towards the nose assembly, a lever positioned in the magazine assembly, and a pin connected to the lever, the pin being configured to connect the lower contact arm and the upper contact arm when more than the predetermined number of fasteners remain in the magazine assembly and to disconnect the lower contact arm from the upper contact arm when the protrusion moves the lever when the predetermined number of fasteners remain in the magazine assembly. a housing having an engine receiving portion; a drive engine located in the engine receiving portion, the drive engine comprising a cylinder and a piston reciprocally mounted within the cylinder, the piston comprising a driver configured to move along a drive axis to drive a fastener during a drive stroke; a nose assembly carried by the housing, the nose assembly comprising a fastener drive track configured to receive the driver, and a movable portion biased in a retracted position towards the housing and movable to an extended position away from the housing; a magazine assembly constructed and arranged to feed successively leading fasteners from a supply of fasteners contained therein into the drive track; and an actuation device configured to actuate the drive engine to initiate the drive stroke, the actuation device comprising a contact trip assembly operatively connected to the movable portion of the nose assembly, the contact trip assembly comprising a lower contact arm connected to the movable portion of the nose assembly biased in the retracted position and movable to the extended position with the moveable portion of the nose assembly, and an upper contact arm operatively connected to the lower contact arm; and a trigger assembly comprising a trigger, a trigger arm pivotally supported by the trigger and configured to interact with the upper contact arm, and a dry fire lockout configured to prevent initiation of the drive stroke when a predetermined number of fasteners remain in the magazine assembly and characterized in that the dry fire lock out is configured to prevent initiation of the drive stroke by disengaging the upper contact arm from the lower contact arm; further wherein the magazine assembly comprises a pusher, and wherein the dry fire lockout includes a protrusion of the pusher extending towards the nose assembly, a lever positioned in the magazine assembly, and a pin connected to the lever, the pin being configured to connect the lower contact arm and the upper contact arm when more than the predetermined number of fasteners remain in the magazine assembly and to disconnect the lower contact arm from the upper contact arm when the protrusion moves the lever when the predetermined number of fasteners remain in the magazine assembly. a contact trip assembly operatively connected to the movable portion of the nose assembly, the contact trip assembly comprising a lower contact arm connected to the movable portion of the nose assembly biased in the retracted position and movable to the extended position with the moveable portion of the nose assembly, and an upper contact arm operatively connected to the lower contact arm; and a trigger assembly comprising a trigger, a trigger arm pivotally supported by the trigger and configured to interact with the upper contact arm, and