A surgical stapling instrument includes an anvil defining a plurality of staple forming pockets and a stapling head assembly. The stapling head assembly includes a body, a coupling member capable of actuating the anvil relative to the body, a staple deck defining a plurality of staple openings, and a firing assembly capable of driving a plurality of staples against the staple forming pockets of the anvil. The firing assembly includes a proximal driving body and an array of discrete staple driving segments positioned distal to the proximal driving body. The proximal driving body is slidably housed within the body. The staple driving segments each have a free proximal end. The proximal driving body is capable of simultaneously actuating the array of staple driving segments to drive the plurality of staples against the staple forming pockets of the anvil.