A surgical stapler includes and end effector configured to receive an upper staple cartridge and a lower staple cartridge. The lower staple cartridge includes staple drivers disposed at a non-perpendicular or oblique angle. The staple drivers may be oppositely angled relative to the perpendicular. The staple drivers may further be coupled to an actuation member that pivots the staple drivers to the perpendicular prior to stapling. The actuation members may be actuated by the firing bar and/or by a wedge sled. The upper staple cartridge may also include angled staple drivers that are pivotable to the perpendicular. The upper staple cartridge and/or the lower staple cartridge may also include staple forming pockets. Alternatively, one staple driver may be perpendicular and second staple driver may be at a non-perpendicular angle. The second staple driver may be actuated into an angled stamped recess.