What is 40 cal?

40 cal refers to the .40 Smith & Wesson (S&W) round, which is a pistol cartridge commonly used by law enforcement agencies and civilians for self-defense. The .40 S&W was introduced in 1990 and is a relatively high-pressure round that delivers decent stopping power without excessive recoil. It typically fires a bullet weighing 165-180 grains at a muzzle velocity of 1,000-1,200 feet per second and has an effective range of about 50 yards. While the popularity of the .40 S&W has declined somewhat in recent years, it remains a popular choice among gun enthusiasts and is widely available for purchase.