Abstract: In a powered tool for dimpling a drywall panel and driving a drywall nail through such panel, into a substrate, a dimpler mounted to a nosepiece of the tool so as to be axially movable over a limited range has an annular portion disposed axially beyond the nosepiece. The tool includes a piston and a driving blade joined to the piston and arranged for driving a drywall nail through the nosepiece and the annular portion, for engaging the annular portion near a distal end of the driving blade, and for driving the dimpler outwardly when the piston is impelled from a retracted position toward an advanced position. The annular portion has a frusto-conical bore. The driving blade has a frusto-conical tip fitting thereinto. A workpiece-contacting shoe is adjustable between a right-angled position relative to the drywall panel and an acute-angled position.