[Source] Flashcannons were large, archaic muzzle-loaded projectile weapons based on the same technology as Sevari flashpistols. They were often mounted on large wind riders. Darth Bane, in his days with the Gloom Walkers, once came across three gunboats with flashcannon emplacements. Had it not been for his force abilities, he and the other Gloom Walkers probably would have been mowed down.