Aviation of World War II

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An aviation cannon of Berezin system


B-20 cannon of Berezin system

The gun B-20 (20-mm) has been created by M.E.Berezin in 1944 on the basis of its 12,7-mm of machine gun UB without any design changes, by a replacement of a trunk.

The cannon was created under ShVAK cartridge. As an ammunition all nominal ammunition of automatic control unit ShVAK were applied. Charge pneumatic or mechanical.

Weight of a gun of 25 kg. Rate of shooting for synchronous version 600 of shots/minutes, for turret and wing - 800 shots/minutes.

Weight of a shell 96 g, an initial missile velocity of 800 m/s.

The gun was installed on the Il-2, Yak-1, Yak-3P, Yak-7b, LaGG-3, La-5, La-7, Tu-2 and Il-10 aircraft.

In 1946, the electrified B-20E version for the Tu-4 turrets went into production, where it was installed before the adoption of the HP-23 cannon.

In 1944, 2275 B-20 guns were produced, in 1945 - 7240, in 1946 - 440, in 1947 - 780, in 1948 - 1686, in 1949 - 2931. At this point, their production was discontinued.

The reliability of the B-20 cannon was lower than required, which was confirmed by the tests of the three-point La-7 at the Air Force Research Institute from September 10 to October 10, 1945. Of the three aircraft (serial numbers 45214414, 45214415, 45214416), on one, it was not possible to achieve the required indicator of 5000 shot from one aircraft without shell failures. On the first fighter, this figure was 3275 shells, on the second - 3222, on the third - 3155. An attempt to solve problems in the reliability of the B-20 cannons was fundamentally the installation of the NS-23 cannon of 23 mm caliber on the La-7. The aircraft with new weapons was tested from 20 to 31 July 1945, the results were again disappointing - the weapon did not work reliably. More successful were repeated tests of the La-7 fighter armed with NS-23 guns, which took place from October 2 to 10, 1945. The NS-23 gun, along with the B-20, was put into service. It is regrettable that the B-20 was chosen for the La-7.


  • "The history of air armament." /Alexander Shirokorad/