40 S&W Ammo

The .40 S&W is a rimless pistol cartridge developed jointly by American firearms manufacturers Smith & Wesson and Winchester in 1990. 

The .40 S&W was developed as a law enforcement cartridge designed to duplicate performance of the Federal Bureau of Investigation's (FBI) reduced-velocity 10mm Auto cartridge which could be retrofitted into medium-frame (9mm size) semi-automatic handguns.

The .40 S&W cartridge has been popular with law enforcement agencies in the United States, Canada, Australia, and Brazil. While possessing nearly identical accuracy, drift and drop as the 9mm Parabellum, it also has an energy advantage over the 9mm Parabellum and .45 ACP, and a more manageable recoil than the 10mm Auto cartridge.

Other names for the .40 S&W are:

(Source: Wikipedia)