Medium machine gun

A medium machine gun or MMG, in modern terms, usually refers to a belt-fed automatic firearm firing a full-power rifle cartridge and typically weighs from 15 to 40 pounds (6.8 to 18.1 kg). MMGs usually have some type of provision for extended firing, such as a removable or extra-heavy barrel, cooling fins, or a water cooling jacket, but are light enough to be used with a bipod. They occupy a gray area between light machine guns and heavy machine guns.

Two features which have remained somewhat constant, however, are some added ability for greater fire over automatic rifles, and the ability to be used in both light infantry support roles on a bipod, but also on mounts and tripods. While heavy machine guns (HMG) are mostly fired from heavy mounts, and light machine guns (LMG) are usually operated with bipods, MMGs have historically been used in both. Heavy machine guns are either crew-served or mounted, while MMGs are usually operated by one to two soldiers. Light machine guns and automatic rifles are often an individual weapon with a fixed, naked barrel. On the other hand medium machine guns have usually had more endurance of some sort, such as the aforementioned heavier barrel, barrel-change, fins etc.