Abstract: A powder-actuated fastening tool is provided with a return pawl slideable within a pawl-holder fixed to the barrel-holder, between a piston engaging position, wherein the pawl, protruding through a longitudinal slot in the barrel engages the piston during the opening of the tool, while at least one boss, formed on the pawl, engages a first plane milled surface of the barrel, and a cocked position, where a second plane milled surface of the barrel, more remote from the barrel axis than the first surface, engages the boss to retract the pawl, the two milled surfaces being connected by a transverse groove which the boss can engage to maintain the barrel in its locked and non-cocked position.