A 40 caliber pistol is a type of handgun that uses 40 Smith & Wesson (S&W) caliber ammunition. 40 S&W is a popular cartridge for self-defense and law enforcement, and it is known for its good balance of power and recoil. 40 caliber pistols are typically semi-automatic, meaning that they can fire multiple rounds without the need to manually cock the hammer or slide after each shot.
40 caliber pistols have been around for over 30 years, and they have been used by law enforcement and civilians alike. They are popular for self-defense because they are relatively powerful and easy to control. 40 caliber pistols are also popular for target shooting and competition shooting.