The .22 Hornet is a vermin, small-game and predator centerfire rifle cartridge. It is considerably more powerful than the .22 WMR and the .17 HMR, achieving higher velocity with a bullet twice the weight. The Hornet also differs very significantly from these in that it is not a rimfire but a centerfire cartridge. This makes it handloadable and reloadable, and thus much more versatile. It was the smallest commercially available .22 caliber centerfire cartridge until the introduction of the FN 5.7x28mm.
The .22 Hornet fills the gap between such popular varmint/predator cartridges as the .22 WMR and the .223 Remington. In regard to muzzle velocity, muzzle energy and noise, it is well suited to vermin and predator control in relatively built-up areas.
Factory ammunition is widely available from all major manufacturers, generally with bullets weighing 34, 35, 45, or 46 grains (2.2, 2.3, 2.9, or 3.0 g), with bullets invariably either hollow point or soft point. Muzzle velocity typically is in the 2,500 to 3,100 ft/s (760 to 940 m/s) range, and muzzle energy is just over 700 ft·lbf (950 J) for factory ammo fired from a rifle. (Velocities and energies are less when Hornet ammunition is fired from short-barreled firearms.)
Published handload data from major handloading-product companies shows how versatile the .22 Hornet can be. According to the Hodgdon reloading data, the heavier bullets show a serious affinity for Lil'Gun smokeless powder to produce much higher velocities than other powder with heavy bullets in this small case.