Gast gun

A Gast gun is a type of autocannon or automatic weapon utilizing the Gast principle. The Gast principle is a specific type of multi-barrel firearm action where one barrel's firing action drives the mechanism for the other barrel(s). Typically, two barrels are linked mechanically so that the recoil from firing one round is used to cycle the action of the other. This results in a very high rate of fire.

The Gast principle, named after Karl Gast, who patented the design in 1916, offers a mechanically simple way to achieve rapid firing without requiring an external power source to cycle the action. This differentiates it from Gatling-type guns, which also have multiple barrels but rely on an external motor for operation.

The primary advantage of a Gast gun is its high rate of fire combined with its relatively simple and robust mechanical design. This makes it potentially lighter and more reliable than comparable externally powered systems. However, Gast guns can be complex to manufacture and maintain, and their recoil forces can be significant.

Notable examples of weapons using the Gast principle include various aircraft autocannons, particularly some Soviet/Russian designs.