Medium machine gun

A medium machine gun (MMG), in modern terms, usually refers to a belt-fed machine gun firing a full-powered rifle cartridge, and is considered "medium" in weight (15–40 lb or 6.8–18.1 kg). Medium machine guns are light enough to be infantry-portable (as opposed to a heavy machine gun, which completely relies on mounting onto a weapons platform for operational stability and mobility), but still cumbersome enough to require a crew for optimal operational efficiency (as opposed to a light machine gun, which can be operated to full capacity by only a single gunner).