Light machine gun

A light machine gun (LMG) is a machine gun designed to be employed by an individual soldier, with or without an assistant, and as a front-line infantry support. Light machine guns are often used as squad automatic weapons.
A light machine gun may be identified either by the weapon or by its tactical role. It is used to fire in short 8 -10 round bursts, usually from a bipod; a sustained-fire mount such as a tripod is a characteristic of a medium machine gun. Some machine guns - notably General purpose machine guns - may be deployed as either a light machine gun or a medium machine gun. As a general rule, if a machine gun is deployed with a bipod it is a light machine gun; if deployed on a tripod it is a medium machine gun - unless it has a caliber of about 10mm or larger, making it a heavy machine gun. Modern light machine guns often fire smaller-caliber cartridges than medium machine guns, and are usually lighter and more compact.
Light machine guns, such as the British Lewis, were first introduced in World War One to boost the firepower of the infantry. By the end of World War II, light machine guns were usually being issued on a scale of one per section or squad, and the modern infantry squad had emerged with tactics that were built around the use of LMGs.
It is possible to fire a light machine gun from the hip or on the move, but this is generally inaccurate. They are usually fired from a prone position using a bipod. Many light machine guns (such as the Bren gun or the M1918 Browning Automatic Rifle) were magazine-fed. Others, such as the MG 34, could be fed either from a belt or a magazine. Modern light machine guns are designed to fire more rounds of a smaller caliber and as such tend to be belt-fed. Some LMGs, such as the Russian RPK, are modifications of existing assault rifleFN Minimi, are capable of firing from either an ammunition belt or a detachable box magazine. Lighter modern LMGs have enabled them to be issued down at the fireteam level and at two or three at the section/squad. designs. Adaptations generally include a larger magazine, a heavier barrel to resist overheating, a more robust mechanism to support sustained fire and a bipod. 
 list of modern light machine gun-

• FN Minimi (5.56x45mm NATO)
  • M249 Squad Automatic Weapon (5.56x45mm NATO)
  • Mk 48 Mod 0 (7.62x51mm NATO)
• CETME Ameli (5.56x45mm NATO)
• Ultimax 100 (5.56x45mm NATO)
• Vektor Mini-SS
• IMI Negev (5.56x45mm NATO)
• Pecheneg machine gun (7.62x54mmR)
• Heckler & Koch MG4 (5.56x45mm NATO)
• Ares Shrike 5.56 (5.56x45mm NATO)
• Stoner LMG (5.56x45mm NATO)
• Colt Automatic Rifle (5.56x45mm NATO)
• Steyr AUG H-BAR (5.56x45mm NATO)
• RPK-74 (5.45x39mm)
• L86 LSW (5.56x45mm NATO)
• Heckler & Koch MG36 (5.56x45mm NATO)
• INSAS LMG (5.56x45mm NATO)
• SAR-21 LMG(5.56x45mm NATO)