Abstract: An apparatus for driving offset fasteners including a pneumatic body, piston housing, reciprocating piston and cartridge. The cartridge includes a stepped track plate and spring member. The spring member and plate cooperate to secure and urge the offset fasteners successively into the piston housing. Connected to an end of the reciprocating piston is a striker bar for driving the offset fasteners out of the piston housing. The piston housing includes a biasing member for preventing an offset fastener from entering the piston housing immediately after an offset fastener has been ejected.