The M3 'grease gun’ was a rude, crude, effective submachine gun that saw service from the Korean War through the late 1990s. The M3 "grease gun" was one of the simplest, ugliest, and cheapest personal weapons ever fielded by the U.S. military. But, as one U.S. Marine combat veteran recalled, what this crude submachine gun lacked in looks, it more than made up for that with brutal effectiveness. "The first time I went to use my rifle, it went 'click', so I busted it over a rock and picked up a dead Marine's grease gun," said USMC Korean War veteran...
