A staple apparatus comprising: a staple head movable in a first staple direction from a head retracted position to a head extended position; and an indexing apparatus comprising: an index biasing member; and an indexing member positioned at least partially within an indexing area and biased with the index biasing member toward a member extended position relative to the indexing area, the indexing member movable in a first indexing direction from the member extended position to a member retracted position relative to the indexing area, wherein the first indexing direction comprises a directional component comprising the first staple direction, the indexing member defining a rung travel path and further comprising an indexing tab comprising a ramp surface positioned to taper the rung travel path in the first indexing direction, and the indexing tab further comprising a shoulder positioned past at least a portion of the ramp surface in the first indexing direction, wherein the indexing apparatus further comprises a cover member at least partially defining the indexing area, the cover member comprising a staple chain slot passing through the cover member to the indexing area and wherein the cover member includes a plurality of grooves extending in the first indexing direction and facing the indexing area, the plurality of grooves comprising a first pair of grooves (1203a, 1203b), characterized in that the plurality of grooves further comprises a second pair of grooves (1205a, 1205b), a staple head movable in a first staple direction from a head retracted position to a head extended position; and an indexing apparatus comprising: an index biasing member; and an indexing member positioned at least partially within an indexing area and biased with the index biasing member toward a member extended position relative to the indexing area, the indexing member movable in a first indexing direction from the member extended position to a member retracted position relative to the indexing area, wherein the first indexing direction comprises a directional component comprising the first staple direction, the indexing member defining a rung travel path and further comprising an indexing tab comprising a ramp surface positioned to taper the rung travel path in the first indexing direction, and the indexing tab further comprising a shoulder positioned past at least a portion of the ramp surface in the first indexing direction, wherein the indexing apparatus further comprises a cover member at least partially defining the indexing area, the cover member comprising a staple chain slot passing through the cover member to the indexing area and wherein the cover member includes a plurality of grooves extending in the first indexing direction and facing the indexing area, the plurality of grooves comprising a first pair of grooves (1203a, 1203b), characterized in that the plurality of grooves further comprises a second pair of grooves (1205a, 1205b), an index biasing member; and an indexing member positioned at least partially within an indexing area and biased with the index biasing member toward a member extended position relative to the indexing area, the indexing member movable in a first indexing direction from the member extended position to a member retracted position relative to the indexing area, wherein the first indexing direction comprises a directional component comprising the first staple direction, the indexing member defining a rung travel path and further comprising an indexing tab comprising a ramp surface positioned to taper the rung travel path in the first indexing direction, and the indexing tab further comprising a shoulder positioned past at least a portion of the ramp surface in the first indexing direction, wherein the indexing apparatus further comprises a cover member at least partially defining the indexing area, the cover member comprising a staple chain slot passing through the cover member to the indexing area and wherein the cover member includes a plurality of grooves extending in the first indexing direction and facing the indexing area, the plurality of grooves comprising a first pair of grooves (1203a, 1203b), characterized in that the plurality of grooves further comprises a second pair of grooves (1205a, 1205b),