View source for Mauser BK-27

[[File:Mauser BK-27 LKCV.jpg|thumb|Aircraft-mounted Mauser BK-27]]

The '''BK 27''' (also '''BK27''' or '''BK-27''') (German acronym for "Bordkanone", translation: on-board cannon) is a 27&nbsp;mm [[autocannon]] manufactured by [[Mauser]] (a subsidiary 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 new series of 27x145 mm projectiles with a typical weight of 260 g (9.2 oz). It uses a linked feed system, but a '''BK 27 Linkless''', with a new linkless feed system intended to improve reliability, has been developed for the [[Eurofighter Typhoon|Eurofighter]]. 

The Mauser BK 27 is used in the [[Panavia Tornado]], the [[Dassault-Breguet/Dornier Alpha Jet|Alpha Jet]], the [[JAS 39 Gripen]], and the [[Eurofighter Typhoon]]. At one time the [[USAF]] hoped to license its production for the [[F-35 Lightning II|F-35]] Lightning II joint strike fighter, but those plans have been cancelled in favour of the cheaper [[GAU-12 Equalizer#GAU-22/A|GAU-22/A]].

Recently [[Rheinmetall]] developed also modified, remote controlled naval versions, the '''MN 27 GS''' and the '''MLG 27''' fully automatic naval guns, applied on many ships of the [[German Navy]]. 99 MLGs 27 have been ordered by the German Navy so far.<ref>http://www.rheinmetall-defence.com/index.php?lang=2&fid=962</ref> 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.

The belted-link ammunition box is positioned to the side of the gun-feed mechanism and a floating buffer system imposes a very small recoil and vibration load on the airframe of the aircraft. Spent cartridge cases and empty links are ducted from the rear of the gun into a collection bay immediately behind the gun. Automatic ram air purges the gun compartment and spent cases bay during and after firing.

The weapon has a very good hit-accuracy and one of its main strengths is the cannon’s ability to achieve a full 1700-rounds-per-minute rate of fire almost from the first round. This is an important asset, particularly if the cannon is being used against a fast-moving target. Targeting of the cannon is done through the aircraft’s head-up-display (HUD). When the cannon is selected in the cockpit, a firing predictor is projected onto the HUD; this depicts a moving line (continuously compacted impact line), or snake, that predicts where the next few rounds of cannon fire will go. The cannon can be aimed by using either a prediction sight or, in the case of the F3, a radar-designated sight.

The cannon has a very high muzzle velocity and its high rate of fire, coupled with its ability to fire several different types of high-explosive shells, make it equally suitable for both interceptor- type aircraft and ground-attack aircraft alike. The system is relatively compact, extremely robust and its simple, rugged design makes it highly reliable.<ref>http://www.raf.mod.uk/equipment/mauserandaden.cfm</ref>
== Operators ==
;{{AUT}}
* [[Austrian Air Force]]
;{{BOL}}
* [[Bolivian Air Force]] 
;{{BEL}}
* [[Belgian Air Component]] 
;{{CMR}}
* [[Cameroon Air Force]] 
;{{CAN}}
* [[Top Aces Incorporated]] 
;{{CZE}}: 
* [[Czech Air Force]]
;{{CIV}}
* [[Côte d'Ivoire Air Force]] 
;{{EGY}}
* [[Egypt Air Force]] 
;{{FRA}}
* [[French Air Force]] 
;{{GER}}
* [[German Air Force]]
;{{HUN}}: 
* [[Hungarian Air Force]]
;{{ITA}}
* [[Italian Air Force]] 
;{{MAR}}
* [[Royal Moroccan Air Force]] 
;{{NGR}}
* [[Nigerian Air Force]] 
;{{POR}}
* [[Portuguese Air Force]] 
;{{QAT}}
* [[Qatar Air Force]]
;{{RSA}}:
* [[South African Air Force]] 
;{{SAU}}
* [[Royal Saudi Air Force]]
;{{SWE}}:
* [[Swedish Air Force]]
;{{ESP}}
* [[Spanish Air Force]]
;{{THA}}
* [[Royal Thai Air Force]] 
;{{TOG}}
* [[Military of Togo|Togo Air Force]] 
;{{UK}}
* [[QinetiQ]] 


==Specifications==
{{multiple image
|align= right
|width= 150
|image1= Mauser BK-27.jpg
|width1= 
|caption1= Helicopter-mounted Mauser BK-27
|image2= Autocannon MLG27.jpg
|width2= 
|caption2= MLG 27 remote controlled revolver cannon onboard an [[Elbe class replenishment ship|''Elbe'' class tender]] of the [[German Navy]]
|image3= MLG auf EGV.JPG
|width3= 
|caption3= MLG 27 onboard a [[Berlin class replenishment ship]] of the German Navy
}}
*'''Type''': single-barrel [[revolver cannon]]
*'''Caliber''': 27&nbsp;mm x 145 (1.06&nbsp;in)
*'''Operation''': [[revolver cannon|revolver]]
*'''Length''': 2.31 m (7&nbsp;ft 7 in)
*'''Weight (complete)''': 100&nbsp;kg (220&nbsp;lb)
*'''Rate of fire''': 1,700 rpm (+/- 100rpm)
*'''Muzzle velocity''': 1,025 m/s (3,362&nbsp;ft/s)
*'''Muzzle energy''': ~136600 Joule
*'''Projectile weight''': 260 g (9.2 oz)

==References==
{{reflist}}

==External links==
*[http://www.airforce-technology.com/contractors/cannons/mauser2/ Airforce Technology page on the BK 27]
* [http://www.rheinmetall-detec.de/index.php?fid=1122&lang=2&pdb=1 Website of ''Rheinmetall Defence'' ]
* [http://www.rheinmetall-detec.de/index.php?fid=1849&lang=2&pdb=1 Marineleichtgeschütz MLG 27] (Website from constructor)
* [http://www.airforce-technology.com/contractors/cannons/mauser2/ ''Airforce Technology''
* [http://www.waffenhq.de/flugzeuge/bk27.html Mauser BK 27 on WaffenHQ]
* [http://www.ef2000.de/bk27.htm Webseite of the EF2000 ]
* [http://www.raf.mod.uk/equipment/mauserandaden.cfm RAF page on BK 27]

{{Aviation lists}}

[[Category:Automatic cannons]]
[[Category:Aircraft guns]]
[[Category:Modern German weapons]]
[[Category:Rheinmetall|BK-27]]
[[Category:27 mm artillery]]

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