SIG MG 710-3
Encyclopedia
The SIG MG 710-3 is a Swiss
7.62 mm general-purpose machine gun designed and manufactured by SIG - Schweizerische Industrie Gesellschaft
(currently Swiss Arms AG
). Developed as a commercial venture primarily for export since the Swiss Army had already adopted the 7.5 mm MG51
GPMG (chambered for the Swiss 7.5x55mm Schmidt Rubin rifle cartridge), which was produced by the federal arms factory W+F.
machine gun
. These efforts resulted in the SIG MG 710-1 (adapted to use the 6.5x55mm round) and the SIG MG 710-2 (using the 7.92x57mm Mauser
cartridge), while the prototype for the final production version which would become the SIG MG 710-3 (designed in a standard NATO 7.62x51mm caliber) was completed by the mid-1960s. Currently the weapon is in use by the armed forces of Bolivia
, Brunei
and Chile
.
weapon operated by roller-delayed blowback and fires from an open bolt. The machine gun's bolt differs from other contemporary designs employing the short recoil 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 camming 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 fully automatic only fire and a cross-bolt 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
(US) 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 MAG machine gun (a simplified version of the MG42
'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 barrels: a light profile, heavy profile (used in a heavy machine gun role) and special type (used for firing blank ammunition).
The firearm has a fixed stock (metal or wood), detachable bipod and 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 tripod. It is also adapted to use an optical sight (with 2.5x magnification) or a night vision device.
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
7.62 mm general-purpose machine gun designed and manufactured by SIG - Schweizerische Industrie Gesellschaft
Schweizerische Industrie Gesellschaft
Schweizerische Industrie Gesellschaft , or SIG, is the former name of SIG Holding AG, a Swiss company that has been active in various businesses during its more than 150 years of operation. Since the year 2000 the Society has undergone strategic refocus, concentrating on its core compentence in...
(currently Swiss Arms AG
Swiss Arms
SAN Swiss Arms AG is a Swiss manufacturer of small arms. It was known as SIG Arms AG before 2000 when it was acquired by the German investors Michael Lüke and Thomas Ortmeier from parent company Schweizerische Industrie Gesellschaft .-Products:...
). Developed as a commercial venture primarily for export since the Swiss Army had already adopted the 7.5 mm MG51
MG51
The 7.5 mm Maschinengewehr 1951 or Mg 51 is a general-purpose machine gun manufactured by W+F of Switzerland. The weapon was introduced into Swiss service when the Swiss Army initiated a competition for a new service machine gun to replace the MG 11 heavy machine gun and the LMG 25 light...
GPMG (chambered for the Swiss 7.5x55mm Schmidt Rubin rifle cartridge), which was produced by the federal arms factory 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 MG45, a late World War II development of the MG42MG42
The MG 42 is a 7.9mm universal machine gun that was developed in Nazi Germany and entered service with the Wehrmacht in 1942...
machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
. These efforts resulted in the SIG MG 710-1 (adapted to use the 6.5x55mm round) and the SIG MG 710-2 (using the 7.92x57mm Mauser
7.92x57mm Mauser
The 8×57mm IS is a rimless bottlenecked rifle cartridge. The 8×57mm IS was adopted by the German Empire in 1905, and was the German service cartridge in both World Wars...
cartridge), while the prototype for the final production version which would become the SIG MG 710-3 (designed in a standard NATO 7.62x51mm caliber) was completed by the mid-1960s. Currently the weapon is in use by the armed forces of Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
, Brunei
Brunei
Brunei , officially the State of Brunei Darussalam or the Nation of Brunei, the Abode of Peace , is a sovereign state located on the north coast of the island of Borneo, in Southeast Asia...
and Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
.
Design details
The SIG MG 710-3 is an automatic, air-cooled belt-fedBelt (firearm)
A belt or ammunition belt is a device used to retain and feed cartridges into a firearm. Belts and the associated feed systems are typically employed to feed machine guns or other automatic weapons...
weapon operated by roller-delayed blowback and fires from an open bolt. The machine gun's bolt differs from other contemporary designs employing the short recoil method of operation (such as CETME
CETME
CETME is an acronym for Centro de Estudios Técnicos de Materiales Especiales , a Spanish government design and development establishment. While being involved in many projects CETME was mostly known for its small arms research and development...
and Heckler & Koch
Heckler & Koch
Heckler & Koch GmbH is a German defense manufacturing company that produces various small arms. Some of their products include the SA80, MP5 submachine gun, G3 automatic rifle, the G36 assault rifle, the HK 416, the MP7 personal defense weapon, the USP series of handguns, and the high-precision...
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 camming 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 fully automatic only fire and a cross-bolt 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
M13 link
The M13 link, formally Link, M13, is the U.S. military designation for a disintegrating metallic link specifically designed for belt-fed firearms and rounds; it was introduced in the mid-20th century. It is the primary link type for the U.S., and among NATO for 7.62 mm ammunition...
(US) or continuous link German DM1 belt, but only after swapping several parts in the feed block. When used in a light machine gun
Light machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...
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 MAG machine gun (a simplified version of the MG42
MG42
The MG 42 is a 7.9mm universal machine gun that was developed in Nazi Germany and entered service with the Wehrmacht in 1942...
'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
Flash suppressor
A flash suppressor, also known as a flash guard, flash eliminator, flash hider, or flash cone, is a device attached to the muzzle of a rifle or other gun that reduces the visible signature of the burning gases that exit the muzzle. This reduces the chances that the shooter will be blinded in dark...
, has a fixed handle used to remove it. The machine gun uses three types of barrels: a light profile, heavy profile (used in a heavy machine gun role) and special type (used for firing blank ammunition).
The firearm has a fixed stock (metal or wood), detachable bipod and 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 tripod. It is also adapted to use an optical sight (with 2.5x magnification) or a night vision device.