The RheinmetallBordkanone5,orBK-5,was aWWII-era German50 mmautocannonprimarily intended for use against Alliedheavy bombers,such as theUnited States Army Air Forces's (USAAF)Boeing B-17 Flying Fortress.Theshellshad a highmuzzle velocityand significantkinetic energy,allowing them to be fired from distances outside the range of the bombers' defensive guns. The largeexplosivecontent of each shell almost ensured the destruction of any bomber that was hit.[2]
| BK-5 cannon | |
|---|---|
 Rear view of a BK 5 in theNational Museum of the United States Air Force,Dayton,Ohio,showing the circular magazine | |
| Type | Aircraftautocannon |
| Place of origin | Germany |
| Service history | |
| In service | 1944–1945 |
| Used by | Nazi Germany |
| Wars | World War II |
| Production history | |
| Designer | Rheinmetall |
| Designed | 1943 |
| Manufacturer | Rheinmetall |
| Produced | 1943–1945 |
| No.built | approx. 300 |
| Specifications | |
| Mass | 540 kg (1,190 lb) |
| Length | 4.348 m (14.27 ft) |
| Barrellength | 3.037 m (9.96 ft) l/60 |
| Shell | 50×420mm R[1] |
| Caliber | 50mm |
| Rate of fire | 40-45 rounds/min |
| Feed system | 21 rounds |
Rheinmetall was given a contract in 1943 to adapt the 50 mm5 cmKwK39tank gun, from thePanzer IIItank, for aerial use in the twin-enginedMesserschmitt Me 410Hornissebomber destroyer.They were installed asUmrüst-Bausätze( "factory modification" ) 4 in the Me 410 A-1/U4, and, experimentally, in twoMesserschmitt Me 262A-1a/U4 jet fighter prototypes (though these were not used operationally),[3]as theMK 214A cannonof similar caliber was not yet available. An experimental fitment of the BK 5 in an undernoseBola(or "dustbin" ) mount on a small number ofHeinkel He 177A-3 heavy bombers was part of a small force of the bombers that was given the task of suppressingFlakon the Eastern Front nearStalingradearly in the winter of 1942–1943 as the A-3/Rüstsatz5 version, allegedly nicknamed theStalingradtyp.The semi-circular magazine of the BK-5 weapon system held 21 rounds.
Approximately 300 were produced but saw only limited action, most notably in the Me 410 A-1/U4 aircraft that served with theII. GruppeofZerstörergeschwader26(ZG 26). It was also mounted on theJunkers Ju 88.
Intended for long-range shots, the cannon was given a telescopic sight in addition to the Me 410's standard Revi C12C gunsight, in order to make it easier to take long-range shots from outside a bomber's defensive perimeter, as a "stand-off" weapon system. This proved to be more of a hindrance than a help in the turning fights in which the Me 410s often found themselves when engaged by enemy fighters, as the manoeuvring targets easily escaped from the telescopic sight's small field of view, forcing them to use to normal sights instead. Since the BK 5 was almost useless against such small, nimble targets, the use of the telescopic sight was unnecessary in these situations anyway.[4]
As installed in the Me 262, with the muzzle protruding well beyond the nose of the fighter, the cannon was found to be prone to jamming, and if fired at night themuzzle flashtended to temporarily blind the pilot's night vision.[3]
According to the account of the engagements against the USAAF by II./ZG 26 from late February through mid-April 1944, the 53 Me 410Hornisseof thatZerstörergruppeequipped with the BK 5 claimed a total of 129 B-17 Flying Fortress and fourConsolidated B-24 Liberatorheavy bombers, destroyed over five or six interceptions while losing nine of their own Me 410s.[citation needed]
See also
editNotes
edit- ^"Munition der 5 cm Pak 38".michaelhiske.de(in German).Retrieved2023-01-16.
- ^"eeoda.de"(PDF).
- ^abZiegler, Mano, "Me 262: Hitler's Jet Plane", Greenhill Books, London, Stackpole Books, Pennsylvania, 2004,ISBN1-85367-624-1,pages 175-182.
- ^Stocker & Petrick 2007,pp. 32–33, 39.
References
edit
- Stocker, Werner; Petrick, Peter (2007),Messerschmitt Me 210 / Me 410 Hornisse/ Hornet,Midland Publishing,ISBN978-1-85780-271-9.