An applicator instrument for dispensing surgical fasteners includes a housing having an actuator and an elongated shaft extending from the housing. The applicator instrument includes a top stamping disposed within the elongated shaft, and a bottom stamping disposed within the elongated shaft that opposes the top stamping. The applicator instrument has a firing system for dispensing at least one surgical fastener from the distal end of the elongated shaft. An end cap is assembled with the distal ends of the top stamping, the bottom stamping, and the elongated shaft for stabilizing the distal end of the applicator instrument. The end cap has a distal end face with castling for engaging an opposing surface such as surgical mesh overlying tissue. The castling prevents the distal end of the applicator instrument from sliding or moving relative to the opposing surface.