Abstract: A gas-operated firearm having a novel bolt construction that includes a locking roller that delays momentarily the action of the bolt upon the firing of the firearm, such delay permitting the bullet to exit the barrel before the bolt can move. The delay is achieved by tapping a portion of the gas generated by the cartridge only after the bullet passes a gas port in the gun barrel to release the locking roller.

Abstract: A fire arm includes a body and a handle carried thereby as well as first and second barrels secured to the body. The second barrel is secured below the first barrel. A first loading mechanism is located in the body for loading the first barrel and a second loading mechanism is loacted in the body for loading the second barrel. A first magazine is selectively secured to the body for supplying the first loading mechanism and a second magazine is selectively secured to the body for supplying the second loading mechanism. The second magazine is spaced from the first magazine. A firing mechanism, which is located in the body allows a sequential firing of the first and second barrels.