Light machine gunA 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. 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.
Squad automatic weaponA squad automatic weapon (SAW), also known as a section automatic weapon or light support weapon (LSW), is a man-portable automatic firearm attached to infantry squads or sections as a source of rapid direct firepower. Weapons fulfilling this role can be light machine guns, or modified selective-fire rifles fitted with a heavier barrel, bipod and a belt/drum-fed design. Squad automatic weapons usually fire the same cartridge (though heavier-bullet variants are preferred) as the assault rifles or battle rifles carried by other members of the unit.
Machine gunA machine gun is a fully automatic, rifled auto-loading firearm designed for sustained direct fire with rifle cartridges. Other automatic firearms such as automatic shotguns and automatic rifles (including assault rifles and battle rifles) are typically designed more for firing short bursts rather than continuous firepower and are not considered true machine guns. Submachine guns fire handgun cartridges rather than rifle cartridges, therefore they are not considered machine guns, while automatic firearms of caliber or more are classified as autocannons rather than machine guns.
Automatic rifleAn automatic rifle is a type of autoloading rifle that is capable of fully automatic fire. Automatic rifles are generally select-fire weapons capable of firing in semi-automatic and automatic firing modes (some automatic rifles are capable of burst-fire as well). Automatic rifles are distinguished from semi-automatic rifles in their ability to fire more than one shot in succession once the trigger is pulled. Most automatic rifles are further subcategorized as battle rifles or assault rifles.
Magazine (firearms)A magazine, or simply called mag, is an ammunition storage and feeding device for a repeating firearm, either integral within the gun (internal/fixed magazine) or externally attached (detachable magazine). The magazine functions by holding several cartridges within itself and sequentially pushing each one into a position where it may be readily loaded into the barrel chamber by the firearm's moving action.