A surgical stapling instrument, comprising: a first side; a second side; a first housing member, comprising: a first proximal end portion; a first distal end portion; a staple cartridge attachment portion configured to operably support a staple cartridge; and a first longitudinal lock portion extending from said first proximal end portion toward said first distal end portion; a second housing member, comprising: a second proximal end portion; a second distal end portion; a jaw member configured to operably support an anvil configured to deform staples deployed from the staple cartridge; and a second longitudinal lock portion extending from said second proximal end portion toward said second distal end portion; a drive member configured to move a staple driver relative to said staple cartridge attachment portion and said jaw member; and an actuator configured to receive a force thereto, wherein said actuator is configured to be moved between a first position and a second position, wherein said actuator is configured to be moved along said first side when said actuator is in said first position, wherein said actuator is configured to be moved along said second side when said actuator is in said second position, and wherein said actuator further comprises at least one actuator lock portion configured to be aligned with said first longitudinal lock portion and said second longitudinal lock portion; wherein said at least one actuator lock portion comprises a first bearing surface configured to engage said first longitudinal lock portion and a second bearing surface configured to engage said second longitudinal lock portion, and wherein said first bearing surface and said second bearing surface are configured to cam or drive said first housing member and said second housing member toward each other when said actuator is advanced distally. a first side; a second side; a first housing member, comprising: a first proximal end portion; a first distal end portion; a staple cartridge attachment portion configured to operably support a staple cartridge; and a first longitudinal lock portion extending from said first proximal end portion toward said first distal end portion; a first proximal end portion; a first distal end portion; a staple cartridge attachment portion configured to operably support a staple cartridge; and a first longitudinal lock portion extending from said first proximal end portion toward said first distal end portion; a second housing member, comprising: a second proximal end portion; a second distal end portion; a jaw member configured to operably support an anvil configured to deform staples deployed from the staple cartridge; and a second longitudinal lock portion extending from said second proximal end portion toward said second distal end portion; a second proximal end portion; a second distal end portion; a jaw member configured to operably support an anvil configured to deform staples deployed from the staple cartridge; and a second longitudinal lock portion extending from said second proximal end portion toward said second distal end portion; a drive member configured to move a staple driver relative to said staple cartridge attachment portion and said jaw member; and an actuator configured to receive a force thereto, wherein said actuator is configured to be moved between a first position and a second position, wherein said actuator is configured to be moved along said first side when said actuator is in said first position, wherein said actuator is configured to be moved along said second side when said actuator is in said second position, and wherein said actuator further comprises at least one actuator lock portion configured to be aligned with said first longitudinal lock portion and said second longitudinal lock portion; wherein said at least one actuator lock portion comprises a first bearing surface configured to engage said first longitudinal lock portion and a second bearing surface configured to engage said second longitudinal lock portion, and wherein said first bearing surface and said second bearing surface are configured to cam or drive said first housing member and said second housing member toward each other when said actuator is advanced distally.