View source for SIG MG 710-3

{{more citations needed|date=December 2012}}
{{Infobox weapon
|name=MG 710-3
| image= SIG MG 710-3.jpg
| image_size = 300
|caption= A SIG MG 710-3 from the [[Swedish Army Museum]].
|origin=Switzerland
|type=[[General-purpose machine gun]]
<!-- Type selection -->
|is_ranged=yes
<!-- Service history -->
|service=
|used_by=See ''[[#Users|Users]]''
|wars=
<!-- Production history -->
|designer=[[Schweizerische Industrie Gesellschaft|SIG]]
|design_date=1955–1960s
|manufacturer=[[Schweizerische Industrie Gesellschaft|SIG]]
|production_date=
|number=
|variants=
<!-- General specifications -->
|weight={{convert|9.25|kg|lb|2|abbr=on}}
|length={{convert|1143|mm|in|abbr=on}}
|part_length={{convert|559|mm|abbr=on|1}}
|crew=
<!-- Ranged weapon specifications -->
|cartridge=[[7.62×51mm NATO]]
|caliber=
|action=[[Blowback (arms)#Roller-delayed|Roller-delayed blowback]]
|rate=800–950 rounds/min
|velocity={{convert|790|m/s|0|abbr=on}}
|range=100 to 1200 m sight adjustments
|max_range=
|feed=Non-disintegrating DM1 or disintegrating [[M13 link]]ed belt
|sights=Open type sights with rear sliding tangent
}}

The '''SIG MG 710-3''' is a Swiss [[7.62×51mm NATO|7.62 mm]] [[general-purpose machine gun]] (GPMG) designed and manufactured by [[Schweizerische Industrie Gesellschaft|SIG - Schweizerische Industrie Gesellschaft]] (currently [[Swiss Arms|Swiss Arms AG]]). The weapon was developed as a commercial venture primarily for export, since the [[Military of Switzerland#Land Forces|Swiss Army]] had already adopted the 7.5&nbsp;mm [[MG 51]] GPMG (chambered for the [[7.5×55mm Swiss]] [[Schmidt–Rubin]] [[rifle]] [[Cartridge (firearms)|cartridge]]), produced by the federal arms factory [[Waffenfabrik Bern|W+F]].

==Development==
Work on the SIG MG 710-3 machine gun (initially designated the '''Model 55''', changed in 1957 to '''SIG MG 710''') began in 1955 and its design was influenced by the [[MG 45]], a late [[World War II]] development of the [[Nazi Germany|German]] [[MG 42]] [[machine gun]]. These efforts resulted in the '''SIG MG 710-1''' (adapted to use the [[6.5×55mm]] round) and the '''SIG MG 710-2''' (with the [[7.92×57mm Mauser]] cartridge), while the prototype for the final production version which would become the SIG MG 710-3 (chambered in a standard [[NATO]] [[7.62×51mm NATO|7.62×51mm]] caliber) was completed by the mid-1960s. As of 2010, the weapon was in use by the armed forces of [[Bolivia]], [[Brunei]], Chile and [[Liberia]]; despite being a Swiss design, the Swiss Army never adopted the gun.<ref name="jones2009">{{cite book |editor1-first=Richard D. |editor1-last=Jones |editor2-first=Leland S. |editor2-last=Ness |title=Jane's Infantry Weapons 2009/2010 |date=January 27, 2009 |edition=35th |publisher=Jane's Information Group |location=Coulsdon |isbn=978-0-7106-2869-5}}</ref>

==Design details==
The SIG MG 710-3 is an [[Automatic firearm|automatic]], air-cooled [[Belt (firearm)|belt-fed]] weapon operated by roller-[[Blowback (firearms)#Delayed blowback|delayed blowback]] and fires from an [[open bolt]]. The machine gun's bolt differs from other contemporary designs employing the roller-delayed blowback method of operation (such as [[CETME]] and [[Heckler & Koch]] designed weapons), being a 3-piece design that consists of a bolt head with two locking rollers, a striker sleeve and the bolt carrier which is connected telescopically with the bolt head. When a round is chambered pressure from the return spring drives the bolt and carrier assembly forward; simultaneously both rollers engage [[Cam (mechanism)|cam]]ming surfaces which drive the rollers outward from their compressed travel position into recesses in the barrel extension. Upon firing, the bolt carrier and striker assembly recoil to the rear and the geometry of the fixed camming surfaces drives the rollers inward unlocking the bolt breech and increasing the speed at which the striker sleeve withdraws relative to the bolt. As the slower bolt continues rearward it impacts the returning striker sleeve (this impact decelerates the bolt).

The bolt assembly also contains the spring extractor, while a lever case ejector is located at the base of the feed tray. Spent casings are ejected downward. The weapon has a striker firing mechanism, a trigger assembly for [[Automatic firearm|fully automatic]] only fire and a cross-bolt [[Safety (firearms)|safety]] (the "safe" setting disables the bolt catch).

The SIG MG 710-3 is fed from the left side by either [[NATO]] standard disintegrating [[M13 link|M13]] (United States) or continuous link German DM1 belt, but only after swapping several parts in the feed block. When used in a [[light machine gun]] role, the ammunition belt is stored in a sheet metal container that has a 50-round capacity and is attached to the left side of the receiver. The feeding mechanism resembles the one used in the [[FN MAG|MAG]] machine gun (a simplified version of the [[MG 42]]'s feed system) operated with a feed arm driven by the motion of the striker sleeve. The belt is fed in two stages during both the forward and rear movement of the bolt assembly.

The quick-change barrel, ended with a slotted [[flash suppressor]], has a fixed handle used to remove it. The machine gun uses three types of [[barrel]]s: a light profile, heavy profile (in a [[heavy machine gun]] role), and special type (used for firing [[Blank (cartridge)|blank]] [[ammunition]]).

The firearm has a fixed [[Stock (firearms)|stock]] (metal or wood), detachable [[Weapon mount#Bipod|bipod]] and [[Iron sight#Open sights|open-type sights]] (rear sight is a sliding tangent with settings from 100 to 1200 m with 100 m increments). Used as a static heavy machine gun the weapon is placed on a SIG L810 [[Weapon mount#Tripod|tripod]]. It is also adapted to use an [[Telescopic sight|optical sight]] (with 2.5× magnification) or a [[Night vision#Night vision technologies|night vision device]].

==Users==
[[File:SIG MG 710-3 Users.png|thumb|Map with SIG MG 710-3 users in blue]]<!--READ FIRST: This section is for cited entries only. Please do not add entries into this list without a citation from a reliable source. All entries without a citation will be removed. Thank you.-->

*{{flag|Bolivia}}<ref name="jones2009" />
*{{flag|Brazil}} <ref name="SmallArmsToday88braz">{{cite book| last = Ezell| first = Edward| author-link = Edward C. Ezell| title = Small Arms Today| publisher = Stackpole Books| volume = 2nd| edition = | date = 1988
| pages = 47| language = English | isbn = 0811722805| jfm =}}</ref>  
*{{flag|Brunei}}<ref name="jones2009"/>
*{{flag|Chile}}<ref name="jones2009"/>
*{{flag|Liberia}}<ref name="jones2009"/>

==See also==
* [[Rheinmetall MG3]]

==References==
{{reflist}}

==Further reading==
* ''The Directory of the World's Weapons''. Blitz Editions. 1996. {{ISBN|1-85605-348-2}}.

==External links==
* [http://www.bellum.nu/armoury/SIGMG710.html Bellum.nu]
*[http://modernfirearms.net/en/machineguns/switzerland-machineguns/sig-mg-710-eng/ Modern Firearms]
* [https://www.militaryimages.net/media/sig-mg710-3.27928/ MilitaryImages.Net]

{{General Purpose Machine Guns}}
{{Delayed Blowback Firearms}}
{{Sturmgewehr 45 derivatives}}

[[Category:7.62×51mm NATO machine guns]]
[[Category:General-purpose machine guns]]
[[Category:Machine guns of Switzerland]]
[[Category:MG 42 derivatives]]
[[Category:Roller-delayed blowback firearms]]
[[Category:Military equipment introduced in the 1960s]]
[[Category:SIG Sauer machine guns]]