General Electric’s armament division struck it big when it brought Gatling guns back in the late 1950s. The company hoped it could sell different models for almost every conceivable mission.

So less than a decade after introducing the iconic Minigun, the Vermont-based defense contractor developed yet another multiple-barrel light machine gun. The designers expected the new “Microgun” to be an popular alternative to traditional infantry weapons.

But the new weapon quickly became the black sheep of the gun family.

“The effectiveness of a lightweight, small-caliber, high rate-of-fire aircraft machine gun has been proven in Vietnam,” a sales brochure notes. “In an effort to further extend the effectiveness of such weapons and systems, General Electric Company … funded design and development program of a 5.56-millimeter Minigun.”

The gun weighed 28 pounds with an integral electric motor—only three pounds more than the Minigun all by itself. And the Microgun was fewer than 30 inches long, making it shorter than an M-16 rifle.

On top of that, the new machine gun used the same 5.56-millimeter ammunition as that weapon. G.E. touted this as a major selling point.

“[The Microgun has the] lowest cost per round fired because of the inherently lower cost of the 5.56-millimeter round,” the promotional literature boasts. “The … round is a standard stock item in the services.”

Otherwise, the machine gun functioned just like its larger brethren. The designs were based on work Richard Gatling had done almost a century before.

Gatling patented his rapid-firing gun in 1862 and experimented with electric power 30 years later. G.E. revived the idea with modern technology and materials after World War II.