This information is derived from a combination of sources: manufacturer's specifications,
measuruments performed by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI)
and approximation formulas devloped by Genitron.com.
Rankings shown here are based on a 4-inch pistol barrel. Rankings for guns of this caliber in our database will vary based on their actual barrel types and lengths.
In shooting competition the Power Factor is used to determine the competitive division in which a particular handgun/cartridge
can be used. It is a simple calculation of the bullet's mass times its muzzle velocity.
PF = bull. mass x muzzel vel.
TKO-Taylor Knock Out Formula
Developed by big-game hunter John Howard Taylor in the 1940's, this formula calculates the relative effectiveness of bullets for hunting game.
TKO = (bull. mass x muzzle vel. x bull. dia.)/7000
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.