• This cartridge was developed as a joint venture between Winchester and Smith & Wesson. It was an effort to to create a cartridge with the same power as the 10mm Norma round that the FBI had just started using, but in a shorter case. The shorter cartridge would facilitate accuracy and allow use of a smaller, more comfortable grip frame. The .40 S&W has become the cartridge of choice for many law enforcement agencies in the United States.