Now we turn to that most common of rounds which is also, possibly, the most efficient ammunition ever created. There are few creatures on the planet that have not, at one time or another, succumbed to a well-placed .22 rimfire. Not only is the .22LR an excellent training, target, and small game hunting caliber, it can be effective on larger animals, especially from a rifle. A barrel length of 16 inches seems about optimal for the long rifle ammunition. My memory is fuzzy but I seem to recall the .22 short optimizing velocity (and thus energy) from around a 10 inch barrel.
People who butcher cattle and hogs have long relied on a single round of .22LR to humanely kill large, heavy-boned animals. Everything depends on proper placement. For a domestic animal, it is usually not difficult to place the round into the brain resulting in immediate loss of consciousness and death. On game animals and varmints within the effective range of the .22, it is possible to accurately target the central nervous system or the heart. Poachers often target the lungs on deer, especially during cooler weather. This probably causes no more suffering than a similarly placed arrow, and I consider archery hunting quite humane, but I would not take a lung shot on a game animal with a .22LR if I could help it. If I were forced by circumstances to shoot a deer with a .22LR, I would definitely try to make a head shot. I would not depend on a .22 round to penetrate deeply enough on anything other than a broadside shot to reach the vitals of a full-grown whitetail. I think it will most of the time; I just would not depend on it.
How does the .22 do in the analysis done by Ellifritz? I would say not bad, all things considered. The percentage of hits that were fatal is comparable to the mighty .357, while the average number of rounds to incapacitation is actually a little better at 1.38 versus 1.7 – I am not sure what that tells us, though. The “actually incapacitated by one shot” is an adequate 60%. What is most telling about the little rimfire, though, is that nearly a third (31%) of the people shot with it are never incapacitated. Most of these shootings with a .22 are done by “non-professionals”, primarily homeowners confronted by burglars or predators or people targeted in muggings, assaults, or carjacking. The attacker is hit by a round or two of .22LR and decides that he should seek an easier target or possibly – as noted in the post about the .25 ACP, overcomes the defender. Any light, soft bullet pushed at barely transonic velocities is going to lose a lot of energy passing through so much as a heavy coat. A .22 that fails to penetrate at least three or four inches into the chest cavity of a determined attacker is unlikely to stop the fight.
Ellifritz does not have data that I have found relating to the difference between .22 rounds from a rifle versus .22 rounds from a handgun. I am sure the .22 rifle would have a lower percentage of failures to incapacitate. I am also sure that even the best round from a .22 rimfire is not as good a load of buck from shotgun or a round from a .30 caliber centerfire.
Another critical variable not available to us is the type of ammunition used. The .22 is notable in that muzzle velocities can vary by 100% or more depending on the ammunition chosen. A Fiocchi .22 short round has a muzzle velocity of 605 fps versus a CCI Stinger .22LR which has a 32 grain bullet exiting the muzzle at 1640 fps. Either can be fired from any standard-chambered .22 rimfire arm (some rounds such as the Stinger and Velocitor, both from CCI, may not work in arms with very tightly dimensioned match chambers).
The old standard velocity .22LR was what we had mostly when I was a kid, and the muzzle velocity runs somewhere around 1050 to 1100 fps with a 40-grain bullet. We considered the effective range to be 50 yards and that is where we sighted them in. High velocity rounds are probably the most common ammunition used for hunting and plinking these days with an average velocity of around 1280 fps. Almost every manufacturer has an entry in this category with a 36 to 38 grain hollow-point bullet – often available in bulk packages of 300 to 550 rounds -- like Federal and Remington. That approximately 200 fps advantage does not stretch the range much but it does flatten the trajectory a little. Except for, shall we say, special applications where I use subsonics, the higher the velocity the better as far as I am concerned. I have piles of both Remington and Federal bulk-pack stuff as well as CCI Mini-Mags (36-grain @ 1260 fps) in my rimfire ammo crate. These are my plinking and practice rounds for both my long guns and handguns. I would also guess that they constitute at least a plurality if not the majority of the rounds tallied in the Ellifritz study simply because high-velocity rounds are the most widely available and affordable ammunition for most people.
But what if we were to go with hyper-velocity rounds such as the aforementioned Stinger or the 33-grain Remington Yellow Jacket at 1500 fps or the Aguila 30-grain at 1750 fps? Obviously these rounds are trading bullet weight for muzzle velocity to some degree. On the short end of the range, however, that translates into enhanced energy. The muzzle energy for the 30-grain Aguila is stepping over the 200 foot-pounds line at 204. The Stinger is not far behind at 191 foot-pounds. This compares to the usual high-velocity rounds at less than 140 foot-pounds at the muzzle. In a self-defense situation where the attacker is often less than 30 feet away, the enhanced energy of the faster, lighter rounds could make a significant difference.
Weapons vary in how they shoot brands and kinds of ammunition. It happens that all my .22’s “like” CCI Velocitors. That is my ammunition of choice for hunting with my Ruger and Savage rifles. It uses a 40-grain bullet with a wide, shallow hollow point traveling at 1435 feet per second generating 183 foot-pounds of energy at the muzzle. This will provide good penetration in most cases. In the Ruger 10/22, in particular, I believe this would be a reasonably effective deterrent if I were forced to use a .22 in self-defense.
In summary, if a person uses a .22 rimfire for self-defense, it is important to choose the most effective ammunition possible. Accuracy is always critical but more so with the smaller rounds. Happily, it is probably easier to be accurate with a decent .22LR than with almost any other weapon and certainly more economical to practice. A shotgun or a centerfire rifle is the best choice. A centerfire handgun in a caliber like the .40 S&W, .357, or .45 ACP is second-best. I would suggest that the .22LR with hypervelocity ammunition from a rifle is probably a reasonable third-tier choice. A .22 handgun goes down still another tier, but it is still not to be dismissed as a defensive arm for those who have no better option. The key is to find ammunition that functions reliably and accurately in the firearm and to practice diligently for speed and precision.
It is also fairly easy to test penetration with pieces of scrap wood, old phone books, or other similar materials. Better penetration equals a quicker end to the threat. As a reference point, phone books duct-taped tightly together are a pretty tough test, but I would still want a round to penetrate more than two inches into that material.