longbough

Funny you should mention it. I am a doctor of Internal Medicine and I also study defensive shooting. I'll give my opinion on the matter and digress into some other issues on my mind.

Certainly a faster, heavier projectile carries more kinetic energy than a smaller, slower one. However, if a projectile is powerful enough to pass through a target it will not transfer all of its energy into the target (i.e. damage). That’s simple physics. A projectile that stops in a target will. I wouldn’t compare a 9mm to a 50 AE. That wasn’t my intent. But the efficacy of a handgun bullet is not about its ability to kill, but to incapacitate.

Hydrostatic shock may be a bit of a misnomer but it is a real phenomenon. Its importance lies in the ability to help “incapacitate” a target – not to kill a target. This is why JHPs are more effective than ball ammo for defense.

But let’s address some basic misconceptions first.

With the exception of a good, penetrating head-shot a handgun bullet is rarely capable of killing someone on the spot. But the sole objective of using a gun in defense is not to "kill" but to “stop” a target which presents an imminent threat. Two shots from a .45 to a chest has a high probability of stopping a subject only because of the neurological shock from acute traumatic injury to vital organs such as the heart and lungs. The phenomenon of “hydrostatic shock” contributes to the ability to deliver neurological shock. While such injuries may eventually result in death the immediate result, in most cases, is an incapacitated target that is no longer a threat.

So what makes an effective handgun caliber? One that is most successful at incapacitating a target – death and morbidity are just potential complications of stopping the subject.

Since I’m on the subject I might as well cover a few other myths that come up constantly about the defensive handgun:

#1. “The cops didn’t have to shoot the subject 41 times.” Yes and no. Putting aside the unfortunate circumstances of that scenario let’s just consider the tactical perspective of the shooter. If a target’s body doesn't produce a reflexive neurocirculatory collapse after two rounds to the chest then the subject will still be standing. How can this happen? Under great stress extreme levels of epinephrine in an individual might be enough to “protect” them from shock. In a sense it acts to "override" the reflexive response. Often the subject is oblivious to the fact that they've been shot. The simple rule is that, if those first two rounds don’t stop a threat, then the next one will have to be to the head. (i.e. a killing shot)

Contrary to popular belief, punching holes into a torso with bullets is an inefficient way to kill a person. A human being is not made up of hitpoints – human physiology and pathophysiology is much more complex.

Modern defensive handgun technique drill is two shots to the thorax. And if the target remains a threat then a follow-up head shot.

Then why don't cops then go for the "head shot" after a failure to stop from thoracic hits? Police officers are trained to shoot center of mass because it’s an easier target. Consistent head shots under stress require a higher degree of training. I wonder if it’d also be “politically incorrect” for the public to know that a cop is trained to deliver head-shots. But the point is- while COM shots can be 96% effective there’s still 4% left standing.

#2. “Psychopaths and psychotic-druggies are supermen.” It should be no surprise that COM shots are less likely to stop a raging nut because their nervous response is likely blunted from all that epinephrine. But, in a defensive situation against a psycho, you should at least try to hit the chest first. It's still effective in most cases.

#3 “Why not shoot them (people) in the leg?” I hear this question all the time. Shooting the leg is a lousy idea. Let’s start with the basics:
a. A leg shot does not have a high probability of stopping someone. It is less likely to induce neurologic shock than a chest shot (see above) and, contrary to popular belief, does not render the leg muscles useless in most cases.
b. A leg is a harder shot under stress.
c. Should the bullet hit the big femoral artery near the groin the person may bleed a great deall. While the bleeding itself may cause morbidity it will happen over a longer period of time. In the meanwhile they’re still a threat to you until the blood-loss catches up to them.

People appalled by this rationale see it as a justification for killing. Not true. Here’s the part that people (gun-owners and non-gun-owners) should understand:

Only in a situation that requires you stop an imminent threat by violent means should you even present (draw) your firearm. This means that a gun should not be brandished “as a threat” or used in an encounter where such a threat is non-existent (Your opinion may be different but this is how I was trained and is what I believe). If you are armed and you see someone stealing your car - just let it go. By any responsible standard only a complete moron would draw their weapon. Leave it to your insurance.

However, if someone is charging at you with the intent of strangling you then, as long as you feel your life is threatened you would be justified in using your weapon to defend yourself in the fashion consistent with your training. It doesn’t matter if the other person has a weapon. This doesn’t mean you HAVE TO draw your weapon, either. The choice is yours But if you draw it - USE IT!

Let's recap:

1. Don't even present a gun unless you're going to use it.
2. Only use it in the case of imminent mortal danger to you or a loved one.
3. To use it properly put two quick shots (4-5inches apart is optimal) to the thoracic region (chest).
4. If the subject is still a threat then place the next round right between the eyes (Do not shoot the forhead - the frontal portion of the skull is very hard - penetration will likely be suboptimal and a glancing shot can easily ricochet off the skull).

Forgive the digression, but I hope that helps.