The Gryazev-Shipunov GSh-30-2 (ГШ-30-2) or GSh-2-30 is a Soviet dual-barrel autocannon developed for use on certain ground attack military aircraft and helicopters.

The Gast gun was a German twin barrelled machine gun that was developed by Karl Gast of Vorwerk und Companie of Barmen and used during the First World War. Its unique operating system produced a very high rate of fire of 1,600 rounds per minute. The same principle was later used as the basis for the widely used Gryazev-Shipunov GSh-23L series of Russian aircraft autocannon.