Sjögren shotgun

The Sjögren Inertia Shotgun is a 12–16 gauge semi-automatic shotgun that was designed by the Swedish inventor Carl Axel Theodor Sjögren, initially manufactured by AB Svenska Vapen- och Ammunitionsfabriken in Sweden and then by Håndvåbenværkstederne Kjøbenhavn in Denmark. It used an inertia system later revived by the Italian firm Benelli and today widely used in shotguns.
A small number of semi automatic military rifles in 7.62×63mm calibre were based on the Swedish Mauser using the Sjögren system, fed from internal seven round magazines, were also built, and tested by potential buyers, but found no market.