BK 5 cannon

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BK-5 cannon
BK5rear.jpg
rear view of a BK 5 in the National Museum of the United States Air Force, Dayton, Ohio, showing the semi-circular magazine
Type Autocannon
Place of origin Germany
Service history
In service 1944–1945
Wars World War II
Production history
Designer Rheinmetall
Designed 1943
Manufacturer Rheinmetall
Produced 1943–1945
Number built approx. 300
Specifications
Weight 540 kilograms (1,190 lb)

Cartridge 50 mm
Rate of fire 45 rounds per minute.

The Bordkanone 5, or BK 5 for short, was a 50 mm autocannon intended primarily for use against Allied heavy bombers, especially the United States Army Air Forces's (USAAF) Boeing B-17. The large calibre shells had very high momentum, allowing them to be accurately fired from long ranges, well outside the range of the defensive guns mounted on the bombers.

Rheinmetall was given a contract in 1943 to adapt the 50 mm KwK 39 tank gun, from the Panzer III tank, for aerial use in the twin-engined Me 410 Hornisse bomber destroyer. They were installed as Umrüst-Bausätze (Factory Modification) 4 in the Me 410 A-1/U4, and experimentally, in two Me 262 A-1a/U4 jet fighter prototypes (though these were not used operationally),[1] as the MK 214 cannon of similar caliber was not yet available. The semi-circular magazine held 21 rounds.

Approximately 300 were produced and it saw only limited action, most notably in the Me 410 A-1/U4 aircraft that served with the II. Gruppe of Zerstörergeschwader 26 (ZG 26). It was also mounted on the Junkers Ju 88 P-4 night attack[citation needed] aircraft. Intended for long-range shots, the cannon was given a telescopic sight in addition to the Me 410's standard Revi C12C gunsight. This proved to be more of a hindrance than a help in the turning fights in which the Me 410s often found themselves, as the maneuvering targets easily escaped from the telescopic sight's small field of view.[2]

As installed in the Me 262, the cannon was found to be prone to jamming, and if fired at night the BK 5's muzzle flash tended to temporarily blind the pilot's night vision.[1]

According to the account of the engagements against the USAAF by II./ZG 26 from late February through mid-April 1944 mentioned at a German language website,[3] the 53 Me 410 Hornisse of that Zerstörergruppe equipped with the BK 5 - as the Umrüst-Bausätze factory modification designated /U4 for the Me 410 series of aircraft - were said to have to shot down a total of 129 B-17 Flying Fortress and four B-24 Liberator heavy bomber aircraft, distributed over a series of five or six interceptions, all while losing only nine of their own Me 410s.[4]

See also[edit]

Notes[edit]

  1. ^ a b Ziegler, Mano, "Me 262: Hitler's Jet Plane", Greenhill Books, London, Stackpole Books, Pennsylvania, 2004, ISBN 1-85367-624-1, pages 175-182.
  2. ^ Stocker & Petrick, p. 32-33, 39
  3. ^ LuftArchiv.de
  4. ^ [1]

References[edit]

  • Stocker, Werner; Petrick, Peter (2007), Messerschmitt Me 210 / Me 410 Hornisse/ Hornet, Midland Publishing, ISBN 1-85780-271-3 .