Abstract: A pneumatically operated fastener-driving tool, particularly adapted for nailing drywall to the framing of a building, includes a housing, a reciprocator assembly mounted within the housing, and a piston mechanism mounted within the reciprocating assembly for axially driving the fastener into the drywall and underlying framing member. Upon actuation of the tool, the piston is pneumatically driven through a fastener-driving stroke and the reciprocator is reactively driven in an opposite direction. The oppositely driven reciprocator assembly absorbs recoil energy during the piston's driving stroke without transmitting an appreciable amount thereof to the housing, thereby substantially precluding housing recoil during driving of the fastener. At the end of the driving stroke, the reciprocator engages and is decelerated by the piston, thereby reducing housing recoil subsequent to the driving of the fastener.