The subgun? Mass produced, stamped, open bolt subgun similar to the Swedish-K. They got a reputation for being a cheap gun, often with lots of reliability issues due to cheap magazines. Mostly they're pretty reliable, though the ejectors seem to be the common trouble spot. Some law enforcement agencies used them, but really they never caught on. It was such a basic design, the open bolt was a liability, and by then the H&Ks with their MP5s began dominating the scene.

They are offered for sale pretty regularly in the NFA world and are about one step up in price from the MAC series, except without the plentiful aftermarket accessories that make the MAC a better buy. There isn't much history to them, they're not particularly good looking, they're not particularly good shooters, so the demand for them isn't really high. Most end up being a "starter" subgun. Mostly, they lack personality, thus get overlooked.

Uzitalk has a portion of their forum dedicated to the 76. Prolly some good reading there if your interested.