MG 151 cannon
MG 151/15 | |
---|---|
MG 151/20 | |
Type | Aircraft Cannon |
Place of origin | Nazi Germany |
Service history | |
Wars | World War II |
Production history | |
Manufacturer | Waffenfabrik Mauser AG |
Specifications | |
Weight | 42.7 kg |
| |
Cartridge | 15×96mm cartridge |
Caliber | 15 mm |
Rate of fire | 680 to 740 rpm |
Muzzle velocity | 850 m/s[1] |
MG 151/20 | |
---|---|
Type | Aircraft Cannon |
Place of origin | Nazi Germany |
Service history | |
Used by | See users |
Wars |
World War II Algerian War Rhodesian Bush War |
Production history | |
Manufacturer | Waffenfabrik Mauser AG |
Specifications | |
Weight | 42 kg |
Length | 1.76 meters |
| |
Cartridge | 20×82mm cartridge |
Caliber | 20 mm |
Rate of fire | 600–750 rpm |
Muzzle velocity | 700 metres per second (2,300 ft/s) to 785 metres per second (2,580 ft/s)[1][2] |
The MG 151 (MG 151/15) was a 15 mm aircraft-mounted autocannon produced by Waffenfabrik Mauser during World War II. Its 20mm variant, the 20 mm MG 151/20 cannon, was widely used on German Luftwaffe fighters, night fighters, fighter-bombers, bombers and ground-attack aircraft. Salvaged guns saw post-war use by other nations.
Development and wartime history (MG 151/20)
The pre-war German doctrine for arming single-engine fighter aircraft mirrored that of the French. This doctrine favored a powerful autocannon mounted between the cylinder blocks of a V engine and firing through the propeller hub, known as a moteur-canon in French (from its first use with the Hispano-Suiza HS.8C engine in World War I, on the SPAD S.XII) and by the cognate Motorkanone in German by the 1930s. The weapon preferred by the French in this role was the most powerful 20mm Oerlikon of the time, namely the FFS model, but this proved too big for German engines. Mauser was tasked with developing a gun that would fit, with a minimum sacrifice in performance. (As a stop-gap measure, the MG FF cannon was developed and put in widespread use, but its performance was lackluster.)[3]
Production of the MG 151 in its original 15 mm calibre format began in 1940. After combat evaluation of the 15 mm cartridge as the main armament of early Messerschmitt Bf 109F-2 fighters, the cannon was redesigned as the 20 mm MG 151/20 in 1941 to fire a 20 mm cartridge. Combat experience showed that a more powerful explosive shell was preferable to a higher projectile velocity.[2] The MG 151/20 cartridge was created by expanding the neck of the cartridge to hold the larger explosive shell used in the MG FF cannon, and shortening the length of the cartridge case holding the longer 20 mm shell to match the overall length of the original 15 mm cartridge.[2] These measures simplified conversion of the 15 mm to the 20 mm MG 151/20 simply by changing the barrel and making other small modifications. A disadvantage of the simplified conversion was reduction of projectile muzzle velocity from 850 metres per second (2,800 ft/s) for the 15 mm shell to 700 metres per second (2,300 ft/s) for the larger and heavier 20 mm shell.[1] With an AP projectile the new 20mm cartridge could only penetrate around 10-12mm of armor at 300m and at 60 degrees, compared to 18mm penetration for its 15mm predecessor in the same conditions, but this was not seen as a significant limitation.[2] The 20 mm version thus became the standard inboard cannon for the Bf 109F-4 series onwards.[2] The 20 mm MG 151/20 offered more predictable trajectory, longer range and higher impact velocity than the 580 metres per second (1,900 ft/s) cartridge of the earlier MG FF cannon.[1] The MG FF was retained for flexible, wing and upward firing Schräge Musik mounts to the end of the war.[4]
The German preference for explosion rather than armor penetration was taken further with the development of the Minengeschoß ammunition, first introduced for the MG FF (in the Bf 109 E-4), and later introduced for the MG 151/20 as well. Even this improvement in explosive power turned out to be unsatisfactory against the four-engine bombers that German fighters were up against in the second part of the war. By German calculations, it took about 15-20 hits with the MG 151/20 ordnance to down a heavy bomber, but this was reduced to just 3-4 hits for a 30 mm shell, from the shattering effects of the hexogen explosive in the shells used for both the long-barreled MK 103 and shorter barreled MK 108 cannon. Only 4-5 hits with 20 mm calibre cannon were needed for frontal attacks on four-engined bombers, but such attacks were difficult to execute. The 30 mm MK 108 cannon thus replaced the MG 151/20 as the standard, engine-mount Motorkanone centre-line armament starting with the Bf 109 K-4, and was also retrofitted to some of the G-series.[5]
Eight hundred MG 151/20 exported to Japan aboard the Italian submarine Cappellini in August 1943 were used to equip 388 Japanese Kawasaki Ki-61-I Hei fighters.[6] The 20 mm MG 151/20 was also fitted on the Macchi C.205, the Fiat G.55 and Reggiane Re.2005 of the Regia Aeronautica [7] and IAR 81B and 81C of the Romanian Royal Air Force.[8]
Postwar Use
After World War 2, numbers of ex-Luftwaffe MG 151/20 cannon were removed from inventory and from scrapped aircraft and used by various nations in their own aircraft. The French Air Force and French Army aviation arm (ALAT) utilized MG 151/20 cannon as both fixed and flexible armament in various aircraft, including helicopters. The FAF and ALAT jointly developed a rubber-insulated flexible mount for the MG 151/20 for use as a door gun, which was later used in combat in Algeria aboard several FAF/ALAT H-21C assault transport helicopters and on Sikorsky HSS-1 Pirate gunship helicopters. French Matra MG 151 20mm cannons were used by Portugal and Rhodesia[9] fitted to their Alouette III helicopters, while Denel designed its own variant for the South African Air Force.[10]
Users
- Germany[11]
- Finland
- France[11]
- Italian Social Republic
- Empire of Japan
- Portugal
- Romania
- Southern Rhodesia[9]
- South Africa[11]
MG 151 specifications
- Type: single-barrel automatic cannon
- Caliber: 15×96mm
- Operation: Recoil-operated; short recoil
- Length: 1916 mm
- Barrel length: 1254 mm
- Rifling: 8 grooves, right hand twist, 1 turn in 16"
- Weight (complete): 38.1 kg (84 lb)
- Rate of fire: 740 rpm
- Effective range: 1000 m
- Muzzle velocity: 850 m/s (AP-T); 960 m/s (HE-T, HEI-T); 1030 m/s AP(WC)
- Projectile types:
- AP-T weighing 72 g
- HE weighing 57 g. HE filler: 2.8 g
- AP(WC) weighing 52 g
MG 151/20 specifications
Two versions of the 20 mm MG 151 were built. Early guns used a percussion priming system, and later E-models used electrical priming. Some rounds were available with a timer self-destruct and/or tracer (or glowtracer). There were also different types of high-explosive shell fillings with either standard PETN, a mixture called HA41 (RDX and aluminium), and a compressed version where more explosives were compressed into same space using large pressures (XM).
- Type: single-barrel automatic cannon
- Caliber: 20×82mm
- Operation: Recoil-operated; short recoil
- Length: 1766 mm
- Barrel length: 1104 mm/55 calibers
- Rifling: 1 turn in 23 calibers
- Weight (complete): 42.7 kg
- Rate of fire: 750 rpm
- Effective range:800 m
- Muzzle velocity: 805 m/s (M-Geschoss); 705 m/s (HE-T, AP)
- Round types:
Ammunition specifications
German Designation | US Abbreviation | Projectile Weight [g] | Bursting charge [g] | Muzzle Velocity [m/s] | Description |
---|---|---|---|---|---|
Brandsprenggranatpatrone 151 mit L'spur ohne Zerleger | HEI-T | 113 | 2.3 g HE (PETN) + 2.1 g incendiary (Elektron) |
705 | Nose fuze, tracer, no self-destruct |
Brandgranatpatrone 151 | incendiary | 117 | 6.6 to 7.3 g incendiary (BaNO3+Al+Mg) | ? | Nose fuze |
Minengeschosspatrone 151 ohne L'Spur | HE | 95 | 18.6 g HE (PETN) | 805 | Nose fuze, no tracer |
Panzergranatpatrone 151 mit L'spur ohne Zerleger | AP-T | 117 | none (bakelite filling in cavity) | 705 | No fuze, tracer, no self-destruct. Penetration 13mm steel at 60-degree impact, 100m range. |
Panzersprenggranatpatrone 151 | APHE | 115 | 4 g HE (PETN) | ? | Detonation after 5mm steel penetration. |
Panzerbrandgranatpatrone (Phosphor) 151 ohne Zerleger | API | 115 | 3.6 g incendiary (WP) | 720 | No fuze, no self-destruct. Penetration 3 to 15mm of steel. |
Panzerbrandgranatpatrone (Elektron) 151 ohne Zerleger | API | 117 | 6.2 g incendiary (Elektron) | 695 | Optimized for strafing unarmoured ships. No self-destruct. Penetration 15 mm of steel at 75-degree impact angle, 100 m range. Fuze functions after 4 mm steel penetration. |
US derivative
In the late 1940s the US Army reverse engineered the MG151 in order to adapt it to fire .60 caliber rounds; these had been developed for use in an anti-tank rifle. Around 300 of these T17 guns were built. However none saw service despite the availability of 6 million rounds of .60 caliber ammunition.[12] Almost one million rounds were fired during the T17 testing program. The main US version produced, the T17E3, was made by Frigidaire. Further refinements led to the T39 and T51 versions, but these also did not enter service.[13]
See also
References
- 1 2 3 4 Johnson, Melvin M., Jr. Rifles and Machine Guns William Morrow & Company (1944) pp.384&385
- 1 2 3 4 5 Anthony G. Williams (2002). Rapid Fire: The Development of Automatic Cannon, Heavy Machine-Guns and Their Ammunition for Armies, Navies and Air Forces. Airlife. p. 165. ISBN 978-1-84037-435-3.
- ↑ Anthony G. Williams (2002). Rapid Fire: The Development of Automatic Cannon, Heavy Machine-Guns and Their Ammunition for Armies, Navies and Air Forces. Airlife. pp. 161–162. ISBN 978-1-84037-435-3.
- ↑ Anthony G. Williams (2002). Rapid Fire: The Development of Automatic Cannon, Heavy Machine-Guns and Their Ammunition for Armies, Navies and Air Forces. Airlife. p. 163. ISBN 978-1-84037-435-3.
- ↑ Anthony G. Williams (2002). Rapid Fire: The Development of Automatic Cannon, Heavy Machine-Guns and Their Ammunition for Armies, Navies and Air Forces. Airlife. pp. 166–167. ISBN 978-1-84037-435-3.
- ↑ Ki-61 survey. Retrieved on 2009-06-04.
- ↑ Anthony G. Williams & Emmnuel Gustin (2003). Flying guns WWII. Airlife. pp. 274–275. ISBN 978-1-84037-227-4.
- ↑ Anthony G. Williams & Emmnuel Gustin (2003). Flying guns WWII. Airlife. p. 238. ISBN 978-1-84037-227-4.
- 1 2 Peter J.H. Petter-Bowyer. Winds of Destruction: The Autobiography of a Rhodesian Combat Pilot (2005 ed.). 30°. pp. 278–279. ISBN 0-958-4890-3-3.
- ↑ "GA 1 20mm Cannon". Unofficial Website of the South African Air Force. Retrieved 2013-06-18.
- 1 2 3 "An introduction to collecting 20 mm cannon cartridges". European Cartridge Research Association. Retrieved 2013-06-18.
- ↑ Anthony G. Williams (2002). Rapid Fire: The Development of Automatic Cannon, Heavy Machine-Guns and Their Ammunition for Armies, Navies and Air Forces. Airlife. p. 154. ISBN 978-1-84037-435-3.
- ↑ Chinn, George (1951). "Parts VIII and IX". The Machine Gun: Development During World War II and Korean Conflict by the United States and their Allies of Full Automatic Machine Gun Systems and High Rate of Fire Power Drive Cannon. III. pp. 110–152.
External links
Wikimedia Commons has media related to MG 151. |
- Type 151 20mm Cannon
- GA 1 20mm Cannon
- WWII era US Military report on the weapons
- External Image
- Prinz Eugen site containing information
- Aircraft of the Luftwaffe - Gun placements