An end effector for use with a surgical stapling instrument. The end effector comprises a first jaw and a second jaw. The first jaw comprises an anvil comprising a proximal camming member. At least one jaw is movable relative to the other to close the end effector. The second jaw comprises an elongated channel comprising a proximal channel aperture and a staple cartridge insertable into the elongated channel. The staple cartridge comprises a cartridge body and a cartridge pan. The cartridge pan comprises a proximal pan aperture configured to be positioned partially distal to the proximal channel aperture when the staple cartridge is assembled with the elongated channel in an unlocked configuration. The camming member is configured to proximally translate the cartridge pan relative to the cartridge body from the unlocked configuration to a locked configuration during a transition of the end effector to a closed configuration.