|Place of origin||Germany|
|Used by||See users|
|Designer||Mauser (now Rheinmetall)|
|Manufacturer||Mauser (now Rheinmetall)|
|Mass||100 kg (220 lb 7 oz)|
|Length||2.31 m (7 ft 7 in)|
|Barrel length||1.73 m (5 ft 8 in)|
|Caliber||27 mm (1.063 in) caliber|
|Rate of fire||1,000–1,700 rpm (+/− 100 rpm), selectable|
|Muzzle velocity||1,100 m/s (3,600 ft/s)|
|Maximum firing range||Air targets: 2,500 meters
Surface targets: 4,000 metersHigh speed naval targets: 2,500 meters
The BK 27 (also BK27 or BK-27) (German acronym for Bordkanone, "on-board cannon") is a 27 mm (1.063 in) caliber revolver cannon manufactured by Mauser (now part of Rheinmetall) of Germany. It was developed in the late 1960s for the MRCA (Multi Role Combat Aircraft) program that ultimately became the Panavia Tornado.
The BK 27 is a gas-operated cannon firing a series of 27×145 mm cartridges with a typical projectile weight of 260 g (9.2 oz), and a total weight for the complete round of 516 g (1.14 lb). Most models use a linked feed system for the ammunition; however, the Eurofighter Typhoon makes use of a specially developed variant of the BK 27 that uses a linkless feed system instead, which is intended to improve reliability.
The Mauser BK 27 is used in the Panavia Tornado, the Alpha Jet, the JAS 39 Gripen, and the Eurofighter Typhoon. At one time Lockheed Martin was considering a licensed-built version for the F-35 Lightning II.
Rheinmetall has also developed remote controlled naval versions, the MN 27 GS and the MLG 27 fully automatic naval guns, which are installed on many ships of the German Navy. Ninety-nine MLG 27s have been ordered by the German Navy so far. The cannon is a single-barrel, high performance, breech-cylinder gun operated by a fully automatic electrically fired gas-operated system at a selective rate of 1000 or 1700 rounds per minute(+/− 100 rpm). The Mauser BK 27 utilizes pyrotechnic cocking charges to cycle the action.
The BK27 has a 3-4 times lower nominal fire rate than the M61 Vulcan, but its fire rate is constant throughout firing because the cannon does not need to start spinning the barrel/barrels. As a result, in conjunction with the larger caliber, the Mauser BK 27 fires in the first 0.5 s 4 kg of projectiles in contrast to the 2 kg of the M61 Vulcan which also needs about 25 kW electrical power on the maximum fire rate.
The gun mainly fires mine shells as these have the best effect against aircraft, there are also several types of armor piercing shells like the frangible armour piercing shell named Fap 27 mm x 145 mm ammunition/peb327 (DM103).
- Discovery Air Defence Services: Alpha Jet
- Czech Air Force: Gripen
- Hungarian Air Force: Gripen
- Italian Air Force: Panavia Tornado, Eurofighter
- Royal Saudi Air Force: Panavia Tornado, Eurofighter
- South African Air Force: Gripen
- Spanish Air Force: Eurofighter
- Swedish Air Force (under the designation 27 mm automatkanon m/85, 27 mm akan m/85): Gripen
- Royal Thai Air Force: Alpha Jet, Gripen
- Royal Air Force: Eurofighter
- Type: single-barrel, five chamber revolver cannon
- Caliber: 27 mm × 145 (1.063 in)
- Operation: revolver
- Length: 2.31 m (7 ft 7 in)
- Weight (complete): 100 kg (220 lb)
- Rate of fire: 1,000-1,700 rpm selectable (+/− 100 rpm)
- Muzzle velocity: 1,100 m/s (3,600 ft/s)
- Muzzle energy: ~157,300 Joules
- Projectile weight: 260 g (9.2 oz)
- ADEN cannon – comparable British design
- DEFA cannon – comparable French design
- R-23 cannon – comparable Russian design
- M39 cannon – comparable US design
- Ian, V. Hogg; Terry, J. Gander (1998). "Cannon - 20 to 30 mm cannon: 27 x 145 B ammunition (Switzerland)". Jane's Ammunition Handbook. Jane's Information Group. ISBN 9780710617897.
- Lockheed Martin favours German cannon for JSF
- "Archived copy". Archived from the original on 2007-12-04. Retrieved 2010-05-26.CS1 maint: archived copy as title (link)
- "Algerian National Navy, Algeria Naval forces, القوات البحرية الجزائرية, naval defence industry, navy technology, frigates, corvettes, submarines, systems". Navyrecognition.com. 2012-07-25. Retrieved 2019-02-05.
- "Saab Presents First Gripen E to Brazil". Saab. 10 September 2019.