Staple apparatus and methods for stapling

An indexing apparatus for indexing a staple chain, the indexing apparatus comprising:

• a support member;
• an index biasing member;
• 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 being movable in a first indexing direction from the member extended position to a member retracted position relative to the indexing area, 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 comprising a staple chain slot passing through the cover member to the indexing area, wherein the indexing area is defined between the support member and the cover member, 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.