The HST 380 Auto Micro was designed for self-defense and use in small pistols such as the Smith & Wesson Bodyguard. It has a nickel-plated casing and special primer that improve its reliability in semi-automatic handguns. It weighs 99 grains and has a deep, tapered hollow-point to provide consistent expansion. This ammunition does not meet the FBI Ammunition Testing Protocol. With a 3.75-inch test barrel, HST 380 Auto Micro ammunition achieves a muzzle velocity of 1,030 feet per second, a velocity of 990 feet per second at 25 yards, and a velocity of 950 feet per second at 50 yards. Using the same sized test barrel, it measures 235 foot-pounds of muzzle energy.