Rotary cannon

A rotary cannon, or Gatling-type cannon, is a rapid-firing weapon that utilizes multiple barrels in a rotating cluster to provide a sustained rate of fire greater than single-barrelled machine guns or automatic cannons of equivalent caliber. The loading, firing, and unloading functions are performed simultaneously in different barrels as they rotate, and the rotation also provides the barrels some time to cool. The rotating barrel cluster on most Gatling-type guns is powered by an external force such as an electric motor, although gas-operated versions have also been developed.

The cyclic multi-barrel design synchronizes the firing/reloading sequence. Each barrel fires a single shot when it reaches a certain point in the cycle, after which the spent cartridge is ejected and then a new round loaded, and in the process, the barrel cools down somewhat.