Doc Machine Pistol Invention

Doc's friends' whipped out automatic pistols, which they had kept under their clothing. These automatics were fed by sixty-cartridge magazines, curled in the shape of compact rams' horns below the grips. The guns were what is known as continuously automatic in operation--they fired steadily as long as the trigger was held back. Both guns and magazines were of Doc's invention, infinitely more compact than ordinary submachine guns.

- The Man of Bronze (1933) Chapter 15