The Oerlikon 20mm cannon is a 20mm automatic anti-aircraft gun developed in 1914, but remains in use in many countries to this day. In the L70 version, the maximum range of the weapon was about 4,400 meters, with the effective range of the shot not exceeding 1000 meters. The theoretical rate of fire of the weapon was 450 rounds / minute, while in combat conditions it was possible to achieve up to 320 rounds / minute.
The Oerlikon 20 mm cannon was designed by Reinhold Becker as early as 1914 and during the First World War it was produced for the use of the German army. However, in 1919, under the Treaty of Versailles, Germany could not produce this type of weapon, and the patent for the gun was bought by the Swiss company SEMAG, which was later taken over by the company Werkzeug Maschinenfabrik Oerlikon and the last part of the company's name gave the name of the presented cannon. In the interwar period, the license for the production of this plot was sent to many European countries, and in the course of World War II, the production of this weapon was undertaken in the USA and Great Britain. There, too, the plot structure was simplified by Polish engineers, leading to the creation of the Polsten plot. Oerlikon 20 mm cannon in various variants it is used to this day, for example by the US Coast Guard.