Heavy machine gun

The M2 Browning machine gun with a tripod weighs 58 kg (128 lb).

Polish partisans firing a Ckm wz.30 (a Polish-made clone of the American Browning M1917) in 1944.

A heavy machine gun refers to either a larger-caliber, high-power machine gun or one of the smaller, medium-caliber (rifle caliber) machine guns meant for prolonged firing from heavy mounts, less mobile, or static positions (or some combination of the two). The latter meaning is generally thought of as an older meaning, and the former as a modern one, but both weapon types have histories extending back to the 1800s. Furthermore, heavier smaller-caliber weapons continue to be used up to the present.

A classic example of a rifle-caliber heavy machine gun would be a water-cooled Maxim machine gun that was belt fed, had a water jacket, was crew served, and mounted on tripod or wheeled mount. Other types used linkable strips (such as the Hotchkiss) or large magazines. A common example of a heavy-caliber machine gun would be the M2 Browning .50-caliber machine gun. Firearms with calibers larger than 13 to 15 mm are generally thought of as autocannons instead of heavy machine guns.