Previous trademark of semi-auto shotguns invented by Carl Axel Theodor Sjögren in Sweden, and manufactured in Copenhagen, Denmark circa early 1900s.
SJOGREN Models
12 ga., unusual inertia operating system features fixed barrel and fully locked breechblock, marked "AUTOMAT SYSTEM SJÖGREN PATENT" on three lines on frame above trigger guard. Approx. 5,000 mfg. 1907-1909.