Abstract: A power driven electric reversible variable speed screwdriver is provided with a collated screwstrip feeder having a barrel which slides axially with respect to the blade and housing of a power screwdriver gun, is rotatably axially supported on the tool head of the gun in axial alignment with the gun blade, is locked by structure on the housing against rotation on the tool head. The orifice of the barrel is placeable in abutment with a sheet of drywall material to be fastened as the blade and gun housing reciprocates from an extended position relative to the barrel, at which a screw is fed through an opening in the barrel side into the barrel bore, to a retracted position relative to the barrel, at which the tip of the blade extends to an position beyond the barrel orifice to a position determined by rotary adjustment of a link connected to the tool head. The barrel and blade are selectively latchable in the retracted position to permit the screwdriver to be used in uncollated, single screw applications.