Re: Stopping Power.

What stops an aggressor is one of three things:

1. They decide to stop themselves. They may do this at the sight of an armed defender, or they may do this because they don't like getting shot. Either way, nobody but the aggressor has control over this one. No handgun hits hard enough to influence this factor.

2. They stop due to loss of consciousness from blood loss. This can take time. Really, no handgun is going to cause much more speed in blood loss versus any other. Achieving rapid blood loss means hitting high COM and busting the heart or other organs or major arteries. Unless psychological factors come into play, blood loss won't necessarily stop someone fast enough to prevent them from harming you, as the FBI found out in the Miami shoot out.

3. A hit to the brain or upper part of the spine can cause incapacitation from CNS damage. The spine is well protected from a frontal shot, and a very narrow target. The brain is protected by a skull, which is a thicker and tougher than you might expect. The head is also a moving target, and in most circumstances, trying to shoot a head under stress is irresponsible, as you dramatically increase the chances of missing, and the bullet is going somewhere.

So, what does that leave as a criteria for a defensive handgun?

Really, it leaves a shotgun. Handguns aren't ideal tools for self defense.

Except that a gun you have with you is better than one you don't. Handguns offer portability.

Once you have sufficient power to penetrate the chest wall and skull, you've got the ability to poke holes in the bits that may cause someone to stop aggressing.

When you go about poking holes in the aggressor, you want to do it with due speed and accuracy. You don't need a major caliber to do this. What you need is a caliber that will poke a hole repeatedly and quickly, and that you can control.