The First Gas Operated Semi-Auto Pistol - Wildey .45 Win Mag

Firearms designer Wildey J. Moore chased a dream to perfect the world’s first gas-operated semi-automatic pistol.

Moore, a prolific inventor with dozens of patents, first cooked up the idea of the beefy handgun that went on to carry his name while working for Swedish military contractor Carl Gustav in the early 1970s. While the Swedes took a pass on the idea, Moore would patent his concept in 1976.

The pistol bled off powder gases from the barrel via a series of ports, which drove an operating piston to cycle the slide. If you tuned the gas regulator all the way closed, the Wildey would revert to being a manually-operated pistol that the user had to rack manually. The benefit of the design was that the action helped tame the recoil of the .45 Win Mag to reportedly less than that of a .357 Magnum-chambered revolver.

With prototype piston guns in hand, Moore, who went on to work for Winchester at the same time the powerful .45 Win Mag and 9mm Win Mag handgun rounds debuted, struggled through the early 1980s to get his gun to the market.