The 9x23mm Winchester is a pistol cartridge developed as a joint venture by Winchester Ammunition and Colt's Manufacturing Company. The 9x23mm Winchester has a convoluted development history, but was commercially introduced by Winchester in 1996. Marketed primarily to competition shooters as a replacement for .38 Super for International Practical Shooting Confederation, United States Practical Shooting Association and International Defensive Pistol Association competition, the cartridge made a splash, but never really caught on.