The .22 Hornet is a low-end vermin

Vermin

Vermin is a term applied to various animal species regarded by some as pests or nuisances and especially to those associated with the carrying of disease. Since the term is defined in relation to human activities, which species are included will vary from area to area and even person to person...

, small-game

Game (food)

Game is any animal hunted for food or not normally domesticated. Game animals are also hunted for sport.The type and range of animals hunted for food varies in different parts of the world. This will be influenced by climate, animal diversity, local taste and locally accepted view about what can or...

 and predator centerfire rifle cartridge. It is considerably more powerful than the .22 WMR

.22 WMR

The .22 Winchester Magnum Rimfire, more commonly called .22 WMR, .22 Magnum, or simply .22 Mag, is a rimfire rifle cartridge...

 and the .17 HMR

.17 HMR

.17 Hornady Magnum Rimfire, commonly known as the .17 HMR, is a rimfire rifle cartridge developed by the ammunition company Hornady in 2002. It descended from the .22 Magnum by necking down the .22 Magnum case to take a .17 caliber bullet, and it is more costly to shoot than traditional .22...

, 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

Handloading

Handloading or reloading is the process of loading firearm cartridges or shotgun shells by assembling the individual components , rather than purchasing completely assembled, factory-loaded cartridges...

 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

.22 WMR

The .22 Winchester Magnum Rimfire, more commonly called .22 WMR, .22 Magnum, or simply .22 Mag, is a rimfire rifle cartridge...

 and the .223 Remington

.223 Remington

The .223 Remington is a sporting cartridge with almost the same external dimensions as the 5.56×45mm NATO military cartridge. The name is commonly pronounced either two-two-three or two-twenty-three. It is loaded with a diameter, jacketed bullet, with weights ranging from , though the most common...

.