Gas-operated machine guns
A gas-operated firearm is one that uses the energy from a portion of high-pressure gas from the cartridge being fired to work the action in semi-automatic and fully automatic guns. (1- M60 is a family of American general-purpose machine guns firing 7.62×51mm NATO cartridges from a disintegrating belt of M13 links.; 2- FN MAG is a Belgian 7.62 mm general-purpose machine gun, designed in the early 1950s at Fabrique Nationale by Ernest Vervier).
