Gryazev-Shipunov GSh-23

The Gryazev-Shipunov GSh-23 is a twin-barreled 23 mm autocannon developed in the Soviet Union, primarily for military aircraft use. It entered service in 1965, replacing the earlier Nudelman-Rikhter NR-23 and Rikhter R-23. The GSh-23 works on the Gast gun principle developed by German engineer Karl Gast of the Vorwerk company in 1916: it is a twin-barreled weapon in which the firing action of one barrel operates the mechanism of the other. The Gast principle provides a much faster rate of fire for lower mechanical wear than a single-barrel weapon. It cannot match the sustained rate of fire of an electrically operated multi-barrel rotary cannon such as the M61 Vulcan, but does not require an external power source, being powered by the recoil of the floating barrels, somewhat like the action of the German MG-42.