A tool assembly for a surgical stapling instrument includes anvil and cartridge assemblies movable between open and closed positions. The cartridge assembly includes a cartridge body defining a tissue contact surface and rows of staples. The cartridge body defines a first firing channel associated with a first row of staples and a second firing channel associated with a second row of staples. A firing cam is positioned within the first firing channel and translates therethrough during a first axial translation to fire the first row of staples. The first firing cam is biased to move into the second firing channel upon retraction after the first axial translation such that the first firing cam translates through the second firing channel upon a second axial translation to fire the second row of staples.