A surgical end effector can comprise a first jaw comprising a proximal jaw end, a distal jaw end, and a staple cartridge comprising a plurality of staples removably stored therein. The end effector can further comprise a second jaw comprising an anvil, wherein the anvil is configured to deform the staples when the staples are driven from the staple cartridge, and a rotatable shaft, comprising a threaded shaft portion and a distal shaft end. The end effector can further comprise a movable member threadably engaged with the threaded shaft portion, wherein said rotatable shaft is configured to drive said movable member toward said distal jaw end when said rotatable shaft is rotated in a drive direction to drive said staples from said staple cartridge, and a distal bearing positioned in the distal jaw end which rotatably supports the distal shaft end.
