An early design from Gordon Ingram of MAC/M10 fame, the M6 was developed in the 1940s as a tubular receiver submachine gun emulating the ergonomics and appearance of the Thompson SMG. Mechanically, the major distinction was the use of a two-stage trigger, with a gentle press producing semi-automatic fire and a full squeeze initiating full automatic fire; a conventional selector switch is also supplied on some models, like this one, that disables the full auto trigger position when engaged. Blade front and windage adjustable notch rear sights, with the patent, address, model and caliber markings on top of the receiver ahead of the ejector port, fluted barrel with slanted pistol grip, right handed "SAFE/AUTO/SEMI" selector, and smooth pistol grip stock.