A surgical stapling instrument for use with an end effector that has an anvil that is movable relative to a staple cartridge supported in the end effector. The end effector is supported by an elongated shaft that extends from a handle assembly. The staple cartridge has a plurality of unformed staples therein that are formed when the anvil is moved into forming contact therewith. Movement of the anvil is controlled by a firing trigger on a handle assembly. The amount of staple formation achieved is dependent upon the degree to which the firing trigger has been actuated.