40 S&W

The .40 S&W (10×22mm Smith & Wesson) is a rimless pistol cartridge developed jointly by major American firearms manufacturers Smith & Wesson and Winchester. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the Federal Bureau of Investigation's reduced-velocity 10mm Auto cartridge which could be retrofitted into medium-frame (9mm size) automatic handguns.