A gun firing method whereby four projectile segments that are contained in a cartridge case are fired simultaneously which creates a predetermined square pattern on a target to increase the hit probability of the dispersion. Two sets of projectile segments that are contained in the cartridge case, are fired by a gun, spin around the central longitudinal axis of each projectile segment, and provide a powerful square salvo of projectile segments. The dispersion produces a substantial increase in the hit probability when compared to a single shot.