View source for Bofors 57 mm gun

{{Infobox Weapon
|name=Bofors 57 mm
|image=[[File:57 Mk 1.jpg|300px]]
|caption=Bofors 57 mm Mk 1, as mounted on the Swedish Spica-II Class FAC.
|origin={{SWE}}
|type=[[Naval gun]]
<!-- Type selection -->
|is_ranged=yes
|is_artillery=yes
<!-- Service history -->
|service=1966 - present
|used_by=See [[#Users|''users'']]
|wars=
<!-- Production history -->
|designer=[[Bofors|Bofors Defence]]
|design_date=Mark 1: 1964</br>Mark 2: 1981<br>Mark 3: 1995
|manufacturer=Bofors Defence (1966-2006)<br>[[BAE Systems AB]] (2006 onwards)
|unit_cost=
|production_date=Mark 1: 1966<br>Mark 2: 1985<br>Mark 3: 1998
|number=
|variants=Mark 1, Mark 2, Mark 3 & [[Mk 110 57 mm gun|Mk 110]].
<!-- General specifications -->
|spec_label=
|weight=Mark 3: 14,000 kg (weight including 1,000 rounds onboard)<br>6.5 kg (complete round)
|length=
|part_length=
|width=
|height=
|diameter=
|crew=
<!-- Ranged weapon specifications -->
|cartridge=57 mm × 438 mm
|caliber=70 caliber 57 mm
|barrels=
|action=
|rate=Mark 1: 200 rounds/min<br>Mark 2 & Mark 3: 220 rounds/min
|velocity=1,035 m/s (HE round)
|range=8,500 m (HE round)
|max_range=17,000 m (HE round at 45°)
|feed=[[Magazine (artillery)|Magazine]]:<br>Mark 1 - 40 ready rounds, 128 rounds in ready racks in mount.<br> Mark 2 - 120 ready rounds, up to 40 rounds in dual hoists.<br> Mark 3 - 120 ready rounds, up to 40 rounds in dual hoists, 1,000 rounds in mounting.
|sights= Gyro-stabilized in local control.
<!-- Artillery specifications -->
|breech=
|recoil=
|carriage=
|elevation=Mark 1: -10°/+78°(40°/s)<br>Mark 2: -10°/+75°(40°/s)<br>Mark 3: -10°/+77°(44°/s)
|traverse=360°<br>Mark 1 & 2: 55°/s<br>Mark 3: 57°/s
}}

The '''Bofors 57 mm gun''' are a series of dual-purpose naval guns, produced and originally designed by [[Bofors|Bofors Defence]] (now a part of [[BAE Systems]]).

==Design==
The Bofors 57&nbsp;mm has a 120-round magazine and a rate of fire of about 220 shots/minute. The rate of fire and the ability to change ammunition types quickly makes the gun suitable for engaging both aerial and naval targets. Normally a computer aims the gun, giving it high accuracy. However, the crew can also train and aim the gun using instrument panels that are either on or in direct contact with the gun.

==Deployments==
The [[Swedish Navy]] is the primary user of the gun and Bofors Defence has exported it for use by navies of Canada, Croatia, Finland, Indonesia, Malaysia, Mexico, Netherlands, Singapore and Thailand.

{{main|Mk 110 57 mm gun}}
The Mk 3 version with stealth turret housing will enter US naval service as the Mk 110 57 mm gun.

==Versions==
;'''Bofors 57&nbsp;mm/L70''':
;''Bofors 57&nbsp;mm Mk 1'': Bofors developed the Mk 1 from the Bofors 57&nbsp;mm/L60 in 1962. Improvements included a higher rate of fire, the use of new munitions including an improved proximity fuse, water cooling for the gun tubes and a new electro-hydraulic system for rapid training and elevation.  Finland, Malaysia, Norway, Indonesia, Singapore and (the former) Yugoslavia are among the countries that adopted the Mk 1.

;''Bofors 57&nbsp;mm Mk 2'': The Mk 2 was a lighter weight version, which utilized a new servo system. Bofors designed the gun in 1981 and it entered active service on the Stockholm Class [[Corvette]] in 1985. The gun was partly dual-purpose in the sense that it is accurate and agile enough to destroy sea-skimming missiles. Bofors manufactured a total of about 50 Mk 2 guns.

{{main|57 Mk3}}
;''Bofors [[57 Mk3|57 mm Mk 3]]'': The Mk3 is the latest version of the gun. Bofors designed it in 1997 and it entered service in 2002. The gun uses smart ammunition but can also fire the same ammunition as the Mk 2. The stealth variant has a reduced radar profile, in part by hiding the gun barrel when it is not firing. The gun has a small radar mounted on the gun barrel to measure muzzle velocity for fire control purposes.  The gun can change ammunition types instantly, thanks to a dual-feed system.

==Users==
;''Mark 1''
*{{CRO}}:
**[[Kralj class fast attack craft|''Kralj'' class]]
**[[Končar class fast attack craft|''Končar'' class]]
*{{FIN}}:
**[[Finnish minelayer Pohjanmaa|Pohjanmaa class]]
**[[Hämeenmaa class minelayer|Hämeenmaa class]]
**[[Helsinki class missile boat]]
*{{INA}}
**[[Andau class]] ([[Lürssen|Lürssen FPB 57-I]]<ref name = fact>{{cite web |url=http://www.luerssen.de/en/frameset.naval.html |title =Naval vessels as built by Lurssen GmbH |publisher =Lurssen.com}}</ref>)
**[[Mandau class]] (modified version of the [[Republic of Korea Navy|South Korean Navy]]'s [[List_of_Republic_of_Korea_Navy_ships#Patrol_2|Bae Ku class]], which was based on the [[USN|U.S. Navy]]'s [[Asheville class gunboat|Asheville class]])
*{{IRL}}
**[[LÉ Eithne (P31)|Eithne class]]
*{{MAS}}:
**[[Kasturi class frigate]]
**[[Perdana class]] ([[Tiger class fast attack craft|Combattante-II 4AL]]<ref name = fact/>) missile boat
**[[Handalan class]] (Spica-M)
**[[Jerong class]] ([[Lürssen|Lurssen TNC 45]]<ref name = fact/>)
*{{NLD}}
**[[De Zeven Provinciën class cruiser]] (acquired by Peruvian Navy as the [[BAP Almirante Grau (CLM-81)]], guns were removed during a refit in 1988)
[[File:RSS P78 01.jpg|thumb|[[Republic of Singapore Navy#Missile gunboats|RSS Sea Dragon]] with its ''57 mm Mk 1''.]]
*{{SIN}}:
**[[Republic of Singapore Navy#Missile gunboats|''Sea Wolf'' class]] ([[Lürssen|Lurssen TNC 45]]<ref name = fact/>)
*{{SWE}}:
**[[Hugin class]]
**[[HMS Spica (T121)|Spica class]]
**[[Spica II class]]
*{{THA}}
**[[List of equipment in Royal Thai Navy#Fast Attack Craft|Prabbrorapak class]] ([[Lürssen|Lurssen TNC 45]]<ref name = fact/>)

;''Mark 2''
[[File:57 mk2.jpg|thumb|A ''57 mm Mk 2'' firing from a Halifax class frigate.]]
*{{CAN}}:
**[[Halifax class frigate]]
*{{INA}}
**[[Pandrong class]] ([[Lürssen|Lürssen FPB 57-II]]<ref name = fact/>)
*{{MAS}}:
**[[Lekiu class frigate]]
[[File:HMS Gävle.JPG|thumb|Swedish Navy's HMS Gävle]]
*{{SWE}}:
**[[Stockholm class corvette]]
**[[Göteborg class corvette]]

;''Mark 3''
*{{FIN}}:
**[[Hamina class missile boat]]
*{{MEX}}:
**[[Sierra class corvette]]
**[[Durango class patrol vessel]]
*{{SWE}}:
**[[Visby class corvette]]
*{{USA}}:
**'''[[USCG]]''': [[USCGC Bertholf (WMSL-750)|Legend class]]
**'''[[USN]]''': [[Zumwalt class destroyer|Zumwalt class]]
**'''[[USN]]''': [[USS Freedom (LCS-1)|Freedom class]]
**'''[[USN]]''': [[USS Independence (LCS-2)|Independence class]]

==References==
{{reflist}}

==External links==
*[http://dsc.discovery.com/tv/future-weapons/weapons/zone2/mk110/mk110.html Discovery Channel website - Watch the Bofors 57 mm gun fires and reload!]
*[http://web.archive.org/web/20060207135925/http://www.naval-technology.com/contractors/missiles/bofors/ Bofors Defence - Naval Guns and Programmable Ammunition]
*[http://www.navweaps.com/Weapons/WNSweden_57-70_mk123.htm Bofors 57 mm L70]
*[http://www.baesystems.com/ProductsServices/bae_prod_bofors_mm_mk_three.html Bofors 57mm MK3 Naval Gun System]
*[http://www.baesystems.com/ProductsServices/l_and_a_sea_mk110.html 57-mm Mk 110 Mod 0 Naval Gun System]

[[Category:Naval anti-aircraft guns|57 mm]]
[[Category:57 mm artillery]]
[[Category:Naval artillery]]
[[Category:Artillery of Sweden]]
[[Category:Bofors]]

[[Category:2Fix]]