The ShVAK (Russian: ШВАК: Шпитальный-Владимиров Авиационный Крупнокалиберный, Shpitalnyi-Vladimirov Aviatsionnyi Krupnokalibernyi, "Shpitalny-Vladimirov large-calibre for aircraft") was a 20 mm autocannon used by the Soviet Union during World War II. It was designed by Boris Shpitalniy and Semyon Vladimirov and entered production in 1936. ShVAK was installed in many Soviet aircraft including Yakovlev Yak-1, Polikarpov I-153 and I-16, Lavochkin La-5 and La-7, LaGG-3, early Ilyushin Il-2, and Soviet-modified Hawker Hurricane aircraft as well as T-38 and T-60 tanks.

The TNSh was a version of this gun for tanks (Russian: ТНШ: Tankovyi Nudel’man-Shpitalnyi).

Contents 1 Description 2 Specifications 3 Ammunition specifications 4 See also 5 References 6 External links

[edit] Description

The ShVAK 20 mm autocannon is a large-caliber version of the 12.7 mm ShKAS machine gun. Plant INZ-2 began production of 12.7-mm of ShVak machine guns in 1935. During 1935-1936 12.7-mm ShKAS machine gun was rechambered to a 20-mm caliber round and serial production was launched. Some months later the 12.7-mm version has been removed from manufacture altogether.^[1]

The autocannon version differed only in the caliber. It is a gas-operated disintegrating link ammunition belt fed weapon with either cable or pneumatic charging in remote applications. ShVAK ammunition consisted of a mix of fragmentation-incendiary and armor piercing-incendiary rounds. By 1944 ShVAK was supplanted by the 20-mm development of the Berezin UB 12.7-mm machine gun (UBS)^[2], the Berezin B-20, which offered the same performance as 20-mm ShVAK but with the advantage of being significantly lighter.^[3]

[edit] Specifications

• Caliber: 20 mm
• Cartridge: 20×99R
• Rate of fire: 700–800 rounds/min
• Muzzle velocity: 750–790 m/s (2,460-2,592 ft/s)
• Weight: 88 lb (40 kg) without ammunition for the wing version
• Length: 66.1 in (1679 mm) for the wing version

[edit] Ammunition specifications

USSR Designation	US Abbreviation	Bullet Weight [g]	Muzzle Velocity [m/s]	Description
OZ	HEI	96.0	770	Nose fuze, 2.8 g HE + 3.3 g incendiary
OZT	HEI-T	96.5	770	Nose fuze, 2.8 g HE + 3.3 g incendiary, tracer
OF	HE-Frag.	91.0	790	Nose fuze, 6.7 g HE, fragmentation grooves on shell
OFZ	HEI-Frag.	91.0	790	Nose fuze, 0.8 g HE + 3.8 g incendiary, fragmentation grooves on shell
BZ	API-HC	96.0	750	Mild steel projectile case with hardened steel core, surrounded by 2.5 g incendiary, screwed on aluminum, or bakelite ballistic cap
BZ	API-HC	99.0	750	As above but with swaged steel nose cap
BZ	API	96.0	750	Solid steel shot with incendiary in swaged steel cap
BZT	API-T	96.0	750	As above but with tracer in base cavity
PU	TP	96.0	770	Inert filled HEI shell with dummy fuze
PUT	TP-T	96.5	770	Empty solid head projectile with swaged tracer in base cavity

[edit] See also

• List of firearms
• List of common WW2 weapons

[edit] References

• Широкорад А.Б. (2001) История авиационного вооружения Харвест (Shirokorad A.B. (2001) Istorya aviatsionnogo vooruzhenia Harvest. ISBN 985-433-695-6) (History of aircraft armament)
• Koll, Christian (2009). Soviet Cannon - A Comprehensive Study of Soviet Arms and Ammunition in Calibres 12.7mm to 57mm. Austria: Koll. p. 117. ISBN 978-3-200-01445-9. http://www.russianammo.org. 

[edit] External links

Wikimedia Commons has media related to: ShVAK cannon

• 20mm TNSh Tank Gun at battlefield.ru
• THE RUSSIAN AMMUNITION PAGE

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