Hiram Maxim invented the first fully automatic machine gun in the world in 1884. The Maxim gun was recoil-operated and was cooled by a water jacket surrounding the barrel. It was manufactured by Vickers and was sometimes known as the Vickers-Maxim and sometimes just Vickers. These guns were used by every major power. Maxim’s first British patents relating to the development of the Maxim gun were granted in June and July 1883. The first prototype was demonstrated to invited guests in October 1884

British Sten Sub-Machine Gun

The suspect in the Michigan State mass shooting had two 9 mm handguns on him that were purchased legally but were not registered when he was found dead from a self-inflicted gunshot wound, officials say. https://abcn.ws/3YR3Q0R | ABC News