It's the hole that matters

This is probably stupid, but maybe it'll summon a little interest in a newbie's blog. I want to talk about 9mm vs .45ACP. If you like, you can call it 5.56 vs. .308 or any of the other tired out arguments that riddle the gun boards and blogs alike.

These discussions generally use such wildly pseudoscientific terms as "stopping power", "knockdown power", "killing power", "hydrostatic shock" and magic formulas like the Taylor Knockout Formula. Such arguments largely misplace the emphasis on the bullet, but I'll get to that in a minute.

Let's pretend that we're a couple of rational thinkers who want to decide what caliber of pistol or rifle to use for defense or hunting or whatever. We want to kill something, or at least make it stop what it's doing. What are appropriate criteria for choosing such a weapon?

Accuracy. I don't mean go buy the most accurate special-made bolt action rifle. I mean shots that don't go where they're supposed to go don't count. Shot placement is the single most important aspect in stopping an animal (four or two-legged). You need a firearm that you can shoot well. The rest of the points don't matter if you can't hit what you're aiming at.

Cartridge. Now we can talk about what caliber is best. Let's take the .223 vs. .308 discussion for example. I think it covers all of the bases. These two calibers differ in a lot of different areas: cartridge weight, cartridge size, recoil, bullet mass, muzzle velocity, and of course, bullet diameter. There are more, but I think these are the pertinent attributes.

The .223 is lighter, so you can carry more rounds with less pounds. It's also smaller, so a .223 magazine holds more rounds than a similarly-sized .308 mag. The .223 also has less recoil which makes follow-up shots faster and full-auto controllability easier.

"So what!" the .308 enthusiasts will say. "The .223 is a mouse gun! It doesn't have enough stopping power!" "I heard a story about a soldier in [insert current conflict] who shot a bad guy 14 times with that Mattel gun and he kept coming! Use a .308 and that'll put 'em on his ass!"

Without getting all "physics class" on your ass, I'll assert that that's stupid. The impact of the bullet on its target is about the same as the impact to the shooter's shoulder. Deer don't get knocked over backwards by bullets and neither do people.

So what do you use as a measure of incapacitation? In short, it's the hole that matters. There are two ways to incapacitate a target - destroy the central nervous system, or facilitate a rapid loss in blood pressure. If you have any other ideas and can back them up with evidence, I'd like to hear them. CNS shots are hard to make, so we're left with going for rapid blood loss and the best way to do that is to make a big hole. That means it needs to be big around and deep, and surface area of the wound cavity is what we're measuring.

I'm not the best at explaining things, so if you disagree I suggest you do some reading here. I am a believer. If you can come up with a fault in the logic, I 'd like to hear it.

To summarize:

1. Shot placement matters most.
2. Consider all of the differences between calibers, not just wounding ability.
3. When it comes to incapacitation, THE HOLE IS WHAT MATTERS.