Self defense, stopping power, and caliber, Part 5

Wednesday, April 16, 2008 Filed in: Ammunition, General gun stuff, Techniques & Training

(For convenience, you can access all the installments of this series at this link.)

More energy can be a good thing - as long as it actually does something useful.

Last time we discussed the concept of the hollowpoint as a way to increase the frontal diameter of the bullet in the target. I also introduced the idea that it takes energy to expand the bullet, energy that is also needed to push the projectile into something that it needs to reach.

There is no such thing as a free lunch. If we want the bullet to expand, it doesn't happen by magic. Somewhere the energy has to be found to deform the metal used in the bullet, and that energy can only be found in the bullet's own movement. If there is too little to start with, then there won't be enough to continue the bullet on its path.

If the cartridge has insufficient energy, when the bullet expands it will stop forward movement too rapidly, resulting in very shallow wounds that may or may not be effective. This tends to explain the lack of expanding bullets for the venerable .38 Special cartridge - there just isn't enough energy to drive a bullet deeply into the target and expand it at the same time.

How do we get around this problem? Well, the first alternative is to simply switch to a cartridge with more energy. In the case of the .38, we could bump up to the .357 Magnum. The .357 certainly has enough energy! Of course, that energy reserve comes at a price: greatly increased recoil and muzzle blast.

The other alternative is to make a higher energy version of the cartridge we already have. This time-tested tactic results in what's know as "+P" ammunition, which is the designation for a cartridge loaded beyond what is considered "normal" pressure. The idea is to increase the energy delivery of that cartridge to accomplish a specific task. Generally, it works pretty well!

You'll see criticisms on the internet of some +P loadings, usually centered on the idea that "it's not much of an increase in power." If you consider what we've explored in this series so far, you'll realize that it doesn't have to be a "lot" - it just has to be "enough"! If a cartridge at normal pressure can't quite deliver an expanding bullet to where it needs to, but a +P version does, then that is sufficient for the task at hand.

Remember: if the energy doesn't do something useful, then it is wasted from our perspective.

Get away from the idea that you need vast increases in power for defensive applications. You simply need enough power to perform the Twin Tasks. Is it better to have an large reserve amount of energy on tap? That's a question that only you can answer, after being honest about your own abilities and needs.

In the next installment we'll bring together the things we've discussed, and look at the tradeoffs you need to consider to pick your "ideal" self defense cartridge.

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-=[ Grant ]=-

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