A surgical instrument (100) including a frame (110), an elongate portion (140), a drive beam (310) and an end effector (150) is disclosed. The elongate portion extends distally from the frame. The drive beam is disposed at least partially within the elongate portion and is translatable with respect to the elongate portion. The end effector is disposed adjacent a distal end of the elongate portion and includes first (170) and second jaw (160) members. The first jaw member (170) is movable with respect to the second jaw member. The first jaw member includes a proximal camming surface and a distal camming surface thereon. A surgical fastener cartridge is disposed in the first jaw member (170), an actuation portion of the drive beam has an upper member arranged to contact the distal camming surface causing approximation of the jaw members. Proximal translation of the drive beam causes the actuation portion of the drive beam to contact the proximal camming surface effecting opening of the jaw members.
