The US M60 Machine Gun, known as "the Pig," was developed in the years after World War II from two revolutionary German designs, combining the effective belt-feed system of the MG 42 machine gun with the bolt-operating design of the FG 42 rifle. Chambered for the standard NATO 7.62mm round, the M60 was the first US-issue machine gun to have a true quick-change barrel; it was capable of firing 100 rounds per minute in a sustained-fire role, with the gun team only having to change barrels every few minutes.

Adopted in 1957, the M60 came into its own in the jungles, hamlets, and city...