What is fn 40cal?

FN 40cal is a type of handgun cartridge that was developed by Fabrique Nationale (FN) Herstal. It is also commonly referred to as the .40 S&W (Smith & Wesson) caliber. The cartridge was developed in the late 1980s in response to a request by the FBI for a more powerful round that could match the stopping power of the 10mm Auto cartridge, but with less recoil and lower cost.

The FN 40cal cartridge uses a .40-inch (10.16mm) diameter bullet that weighs between 135 and 200 grains (8.8–13.0 g). It has a muzzle velocity of around 1,000–1,200 feet per second (fps) and a muzzle energy of around 400–600 foot-pounds (ft·lbf) depending on the bullet weight and powder charge.

The FN 40cal cartridge is widely used in law enforcement and self-defense applications due to its good balance of power, accuracy, and manageable recoil. It is also popular among competitive shooters in USPSA, IDPA, and other shooting sports.

The FN 40cal cartridge is typically loaded into semi-automatic pistols, including the FN FNS, FN FNX, and FN Five-seveN. Other popular handguns chambered in .40 S&W include the Glock 22, Smith & Wesson M&P, and Sig Sauer P226.