The first of the modern .22 varmint cartridges was the .22 Hornet, developed in the 1920's and introduced as a factory loaded cartridge by Winchester in 1930. The modest Hornet, still reasonably popular, drives a 45 grain bullet at a muzzle velocity (MV) of 2690 fps.

The latest .22 centerfire, as of this writing, is the .22 Nosler. A sign of the times, the .22 Nosler is designed to achieve .22-250 performance in AR-15 type rifles. It boasts a MV of 3500 fps from a 24" barrel. This pretty well summarizes the ballistic evolution of the hot .22's.

However, as sure as the sun rises, there will be more hot centerfire .22's brought to market in the future. It seems as if the interest in this class of cartridge never wanes.

Along the way, the major arms and ammunition companies brought out the .218 Bee (46 grain bullet at 2760 fps), .221 Fireball (50 grain bullet at 2995 fps), .222 Remington (50 grain bullet at 3140 fps), .223 Remington (55 grain bullet at 3240 fps), .22-250 Remington (55 grain bullet at 3680 fps) and .220 Swift (50 grain bullet at 3870 fps). All of these are at least reasonably popular today.

Remington lists the .223 Remington and .22-250 Remington among their 10 best selling centerfire rifle cartridges, with the .223 being number one in sales. The older .222 Remington, although no longer in the top 10 in sales, still sells well. This says something about Remington's success in the field as well as the popularity of the centerfire .22's in general.

Other efforts, such as the .219 Zipper, .220 Rocket, .222 Rem. Magnum, .224 Weatherby, .225 Winchester and .223 WSSM had their moment in the sun, but failed to achieve lasting popularity. The .224 Wby. and .225 Win. were introduced as factory loaded cartridges around the same time as the immensely popular .22-250, with very similar ballistics. The super short and fat .223 WSSM was introduced decades later to compete with the .22-250. The .22-250 took off and the others did not.

All of these centerfire .22's were designed for shooting small game, varmints and small predators at long range (meaning beyond the effective range of .22 rimfire cartridges). There seems to be an appeal to varmint hunting that never wanes. Perhaps shooting small rodents satisfies some primordial urge in Homo sapiens. At ranges around 200 yards it is certainly a challenge to both the shooter and the rifle.

Small targets at long range put an emphasis on accuracy. In the right rifle, all of the centerfire .22's can be superbly accurate. The .222 Remington, in fact, is probably the most accurate hunting cartridge ever introduced. Designed as a varmint cartridge, it was used to set many records in bench rest competition after its introduction.

Part of the great appeal of the centerfire .22's is their mild recoil and relatively tame muzzle blast. Even the largest .22 cartridges, such as the .220 Swift, remain fun to shoot over extended periods of time. Because they are easy to shoot, hunters shoot them well.

Larger caliber cartridges, such as the .243 Winchester, 6mm Remington and .25-06 Remington, can deliver the required accuracy and flat trajectory with varmint bullets, but they kick more and are not as much fun to shoot. Their barrels heat up more rapidly and their ammunition costs are substantially higher, even for reloaders. All of these factors combine to insure the continuing popularity of the centerfire .22's.

However, I would be remiss if I did not point out that the centerfire .22's do have their weaknesses. Principle among them is the relatively poor ballistic coefficient (BC) and sectional density (SD) of their varmint bullets.

Ballistic coefficient is indicative of aerodynamic drag, or how efficiently a bullet flies through the air. The higher the BC, the better a bullet retains its initial velocity and the flatter it shoots.

Sectional density is the square of a bullet's diameter divided by its weight. A bullet with a high sectional density is a long bullet for its caliber; this helps it penetrate well. Given two bullets of the same basic shape, the one with the higher sectional density will also have the higher ballistic coefficient, so to an extent a superior SD and a superior BC go hand in hand.

Unfortunately, in the modern vernacular, bullets for .22 rifles are SD and BC challenged. In other words, they score pretty low in both areas. That is why at extreme long range a varmint bullet from a .243 may actually shoot flatter than a bullet from a hot .22 that starts with a higher muzzle velocity. The light, relatively short .22 bullet loses velocity faster and at long range may actually be traveling slower than the .243 bullet.

This is also why .22 bullets drift so badly in the wind. Wind drift is a function, not so much of velocity, but of the rate of velocity loss. The larger bore varmint calibers, shooting bullets of superior SD and BC, have an advantage over the .22's.

Still, for most varmint shooting most of the time, the centerfire .22's are the way to go. Their mild muzzle blast means that they can be used closer to civilization than the bigger calibers (non-shooters tend to equate noise with danger) and their mild recoil means that more rounds can be fired with greater accuracy over a longer period of time. As much as I appreciate the superior wind-bucking capability of the .243 Winchester, for instance, I prefer the .223 Remington for a long day of shooting.