Subsonic .22LR Terminal Ballistics and Lethality

.22LR is the smallest firearm cartridge in common use today. Common wisdom holds that it is too weak to use for defense against humans or for hunting any animal larger than a raccoon. However there is some evidence that this cartridge is underestimated.

.22LR ammunition is attractive for several reasons:

As I have noted elsewhere, it is a great round for shooting with suppressors: Because .22LR produces so little propellant pressure and volume, suppressors for the caliber can be made very small and light. Furthermore, there is an abundance of subsonic loads on the market, which allow for nearly silent shooting: When shooting slower loads out of my rifles with an Outback suppressor the only audible sound from the gun is the click of the sear releasing the hammer and striking the cartridge rim. The sound of the lead projectile striking a soft target even a hundred yards away is louder to the shooter. (Note that in moderate weather muzzle velocity has to fall below 1000fps to avoid sonic echoes, which increase in loudness and turn into unmistakable sonic cracks as muzzle velocities cross the speed of sound around 1100fps.)

Guns I have reviewed in this caliber include:

So this is a cheap, fun, and accurate caliber. But is it useful for hunting or defense? This is a subject of endless debate. When it comes to defense, of course, we would prefer to avoid confrontation altogether, and failing that would grab a high-powered rifle or shotgun to stop any aggressor. Smaller guns and lighter rounds are a compromise: you sacrifice power and penetration in order to get something more portable and shootable.

Effects on Humans

Common wisdom has it that .380ACP is “barely” enough bullet to qualify as a defensive handgun round, and anything lighter is more likely to enrage an aggressor than to stop him. My favorite study of this subject is An Alternate Look at Handgun Stopping Power by Greg Ellifritz. He analyzed nearly 1800 shootings during violent encounters and came up with some surprising results:

  1. A lot of the time just shooting at someone is enough to get them to stop, regardless of caliber or whether they are hit. I.e., guns “psychologically stop” many assailants. Based on this observation: It’s more important to have a gun – any gun – than to be caught without one.
  2. Determined aggressors do need to be “physically stopped” (incapacitated), and in that case shot placement is far more important than caliber. I.e., largely regardless of caliber: if you hit an assailant in the head they stop 75% of the time. Torso hits stop them 40% of the time. Put another way: How well you shoot is more important than what you shoot.
  3. However, independent of shot placement, calibers below .380ACP are twice as likely to “fail to incapacitate” as the larger calibers. So yes, there is something to the conventional wisdom that if you’re carrying a gun it should shoot something no smaller than .380ACP.

Effects on Deer

I’ve never had a chance to interview someone who was in a gunfight, but I know plenty of hunters. One in particular spent time working around a farm in a reasonably populated area where it was permissible to kill deer to protect crops. Given the out-of-control deer population he had killed too many deer to count. His weapon of choice was a suppressed .22LR rifle from which he shot subsonic .40gr bullets. A good marksman, he would take headshots, aiming for the base of the brain under the ear. His furthest kill was at 160 yards. He reported that most of the time deer he shot would fall down dead on the spot. Some would manage to run a few yards before falling over. The rest of the time deer would fall immediately on their side but begin to kick their legs as if running. He used to think this was a reflexive instinct — that they had taken a lethal shot to the head but that their body didn’t realize it yet — until one day his gun jammed readying for a follow-up shot and the deer climbed to its feet and ran away. That’s the only one that got away.

Do you need a headshot to put down a deer with a .22? This hunter didn’t want to make a study of that question on wild animals, but did admit that once he had a deer standing broadside at 70 yards with its head behind a tree. He decided to put a round in the traditional kill zone of the chest where the heart and lungs are. The deer took off and stopped in a thicket less than 30 yards from where it was shot. The hunter waited half an hour to follow it in. (He explained that this is an ethical way to let animals shot in the chest die: Chasing them as they lose blood pressure just panics them in their final moments.) Sure enough: The deer was as dead as if it had been hit in the chest with a high-powered .30-caliber bullet.

For further reading there are plenty of references on this thread.

Leave a Reply

Your email address will not be published. Required fields are marked *