Abstract: A trajectory compensating device for use with a rifle scope used in aiming a firearm is improved by including in the reticle of the rifle scope two sighting planes and including on the elevational turret of the rifle scope a turret cap which includes an indicia carrying member. The two sighting planes in the reticle are a primary sighting plane and a secondary sighting plane. The elevational turret of the rifle scope includes an indexing mark located thereon. The elevational turret controls the elevational correcting system of the rifle scope by rotation of the turret cap. The indicia carrying member includes at least two indicia markings. One of these indicia markings is correlated to correspond to a calibration distance wherein the rifle scope is sighted in utilizing the primary sighting plane of the reticle.

Abstract: An improvement in gas operated firearms having means for regulating the flow of gas from the barrel of the firearm to the piston which operates the action of the firearm. The improvement is a device which eliminates the necessity of having to change the barrels to accommodate different types of ammunition and loads. The improvement embodies a combined gas regulator and piston receiver associated with the reciprocating piston that actuates the action of the firearm. The combined gas regulator and piston receiver is reversible and in either of its positions fits in sealing relationship against the member which depends from the barrel of the gun and contains the gas orifices that deliver the gas from the barrel, to the regulator. The regulator-receiver has a bore that fits on the forearm shaft. Equally angularly spaced axial passageways are provided of partial circular configuration at the internal diameter of the regulator. An axial bore or passageway is also provided through the regulator.

Abstract: A safety device for guns such as gas operated shotguns having interchangeable barrels. The barrels may be chambered for different-sized cartridges or shells, such as 23/4 inch shells or 3 inch shells. It would be unsafe to load a 3 inch shell into a barrel chambered for 23/4 inch shells. The invention is a safety block or lug which is fitted to the barrel chambered for the smaller size cartridge, the block having a position such that it is not possible to load the larger size cartridge into the gun.