A light machine gun (LMG) is a light-weight machine gun designed to be operated by a single infantryman, with or without an assistant, as an infantry support weapon. LMGs firing cartridges of the same caliber as the other riflemen of the same combat unit are often referred to as squad automatic weapons. Unlike submachine guns, LMGs do not use pistol cartridges.

Characteristics While early light machine guns fired full-powered rifle cartridges, modern light machine guns often fire smaller-caliber rifle cartridges than medium machine guns – generally the same intermediate cartridge fired by a service's standard assault rifle – and are usually lighter and more compact. Some LMGs, such as the Russian RPK, are modifications of existing designs and designed to share the same ammunition. Adaptations to the original rifle generally include a larger magazine, a heavier barrel to resist overheating, a more robust mechanism to support sustained fire and a bipod.

A light machine gun is also defined by its usage as well as its specifications: some machine guns – notably general-purpose machine guns – may be deployed either as a light machine gun or a medium machine gun. Deployed on a tripod and used for sustained fire, it is a medium machine gun; if deployed with a bipod with the operator in a prone position and firing short bursts, it is a light machine gun.

Light machine guns are also designed to be fired from the hip or on the move as a form of suppressive fire intended to pin down the enemy. Marching fire is a specific tactic that relies on this capability.

Lighter modern LMGs have enabled them to be issued down at the fireteam level, with two or three at the section/squad level.

Ammunition feed Many light machine guns (such as the Bren gun or the M1918 Browning Automatic Rifle) were magazine-fed. Others, such as the Hotchkiss M1922, could be fed either from a belt/strip or from a box magazine. Modern light machine guns are designed to fire smaller caliber rounds and, as such, tend to be belt-fed (from a container attached to the gun) or from a detachable drum magazine, but some, such as the FN Minimi, will also accept standard rifle magazine feeding as an auxiliary measure when belted ammunition has been exhausted.

History In 1903, French military theorists noticed that the heavy machine guns of the day were of little use in infantry assaults. They determined that "the machine gun must learn to walk". They researched the possibility of a light machine gun which could be carried by troops. A marching fire tactic was theorised, using incidental suppressive fire, with the advancing troops considered a deadlier threat than the un-aimed bullets, causing the enemy to fall back. The prototype guns were not approved for production, and none were in service when World War I began. The French quickly brought the prototypes to mass production to boost the firepower of advancing infantry.

By the end of World War II, light machine guns were usually being issued on a scale of one per fire team or squad, and the modern infantry squad had emerged with tactics that were built around the use of the LMG to provide suppressive fire.

Selected examples The following were either exclusively light machine guns, had a light machine gun variant or were employed in the light machine gun role with certain adaptations.

Model Country of origin Design date Caliber(s) Weight (base model) kg (lb) Feed system Rate of fire (rounds/min) Model variantsMadsen machine gun1896Various Box magazine450M1902, Rexer, M1916, M1922, M1924, M1949Chauchat (Fusil-Mitrailleur Mle 1915 'CSRG')19078mm Lebel .30-06 Springfield Magazine240/360M1918 CSRG Chauchat(USA)Hotchkiss M1909 Benét–Mercié 19098mm Lebel .303 British .30-06 Springfield Stripper clip fed400–600Bergmann MG15 nA Gun 19107.92×57mm Mauser Belt fed500–600Vickers-Berthier 1910.303 British Box magazine450–600Lewis Gun 1911.303 British .30-06 Springfield 7.92×57mm Mauser Pan magazine 600 (cyclic)Huot automatic rifle1916.303 British Drum magazine 155/475M1918 Browning Automatic Rifle 1917.30-06 Springfield 6.5×55mm 7.92×57mm Mauser Box magazine 650 (cyclic)Wz. 1928 (Poland)Hotchkiss M19221922Various8.5 kg (18.7 lb)Magazine450Type 11 light machine gun 19226.5×50mm Arisaka Stripper clip fed, hopper magazine 500 (cyclic)ZB vz. 26 19237.92×57mm Mauser Box magazine 500FM-24/29 19247.5×54mm French Box magazine450 (cyclic)Maxim-Tokarev19247.62×54mmR Belt fedLmg 2519257.5×55mm Swiss Box magazine ≈500Lahti-Saloranta M/2619257.62×53mmR Magazine450–550Degtyaryov machine gun19277.62×54mmR Pan magazine550Mendoza RM219287×57mm Mauser .30-06 Springfield Box magazine450–650Breda 30 19306.5×52mm Mannlicher–Carcano Stripper clip fed, internal magazine 500 (cyclic)ZB vz. 3019307.92×57mm Box magazine 550–650Bren1935.303 British Box magazine500–520Type 96 light machine gun 19366.5×50mm Arisaka Box magazine 450 (cyclic)Type 99 light machine gun 19397.7×58mm Arisaka Box magazine 800RPK19607.62×39mm4.8 kg (10.6 lb)Drum or box magazine600RPK-74 RPK-16Heckler & Koch HK2119615.56×45mm NATO 7.62×51mm NATOBelt fed or box magazine900HK11EHK13EStoner 631960s5.56×45mm NATO Drum or box magazine1000 (cyclic)Colt Automatic Rifle1970s5.56×45mm NATO Drum or box magazine750 (cyclic)Diemaco LSW (CAN)L86 LSW1970s5.56×45mm NATO Box magazine775 (cyclic)FN Minimi19745.56×45mm NATO (standard) 7.62×51mm NATO Belt fed or box magazine1150 (cyclic)M249 Squad Automatic Weapon (USA) MK 46 machine gun (USA)CETME Ameli19745.56×45mm NATO Belt fed1200 (cyclic)MG82 (Spain)Ultimax 10019775.56×45mm NATO Drum or box magazine600 (cyclic)Steyr AUG H-BAR19775.56×45mm NATO Box magazine750 (cyclic)IWI Negev19855.56×45mm NATO Belt fed or magazine1150 (cyclic)Negev NG720127.62×51mm NATO Belt fed or magazineHeckler & Koch MG41990s5.56×45mm NATO Belt fed885 (cyclic)Heckler & Koch MG361990s5.56×45mm NATO Drum or box magazine750 (cyclic)INSAS LMG1990s5.56×45mm NATO Box magazine650 (cyclic)SAR-21 LMG19965.56×45mm NATO Box magazine650 (cyclic)Ares Shrike 5.562000s5.56×45mm NATO Belt fed or magazine800 (cyclic)Type-81 LMG19817.62×39mm75-round drum or 30-round STANAG 750 (cyclic)BD-15 LMG (Bangladesh)M27 IAR20085.56×45mm NATO Drum or box magazine640 (cyclic)QJB-9519975.8x42mm60900 (cyclic)Colt IAR694020085.56×45mm NATO Drum or box magazine700 (cyclic)Colt 6940E-SG (Singapore)RPD19447.62×39mmBelt fed650

See also Medium machine gun Heavy machine gun Automatic rifle Squad automatic weapon General-purpose machine gun Assault rifle List of machine guns

References