Want to start an unending and probably unwinable argument? Start debating the way to measure "power" in a pistol. To the neophyte this is a strange subject. Don’t we just read those numbers the Ammo manufacturers put out on those nice little charts. The short answer is NO!

Why is this even important? Because handguns do not possess enough power to instantly incapacitate a human aggressor even when the hit is in the heart. And if the targeted subject is not a deadly danger to you, making it imperative that he stops what he is doing RIGHT NOW!, then why are you shooting him? This has several ramifications on just why we teach certain tactical principles but for the moment let us concentrate on what the bullet does or what we would like it to do. I apologize in advance for the necessarily gory details we must examine. I also implore you to examine this subject in depth. What I write here is only a drop in the bucket. Entire books have been written on this subject and we still have little grasp of it.

Essentially the bottom line is this. Handgun projectiles do not impart any sort of "shock" to the subject. The blow from even a .44 Magnum is about the same as that of a muscular Ballerina. If the bullet were capable of knocking down its human target the recoil of the pistol would knock down the firer as well. In short, we look at this subject all wrong if we are looking for some sort of "power", represented by a measure of foot-pounds of kinetic energy, pounds-feet of momentum, or Hatcher Units or RII numbers. None of these measures get anything done in relation to true physical incapacitation.

Handgun bullets bring about incapacitation by putting a hole in something important. If it is a hole in an element of the Central Nervous System (CNS), like the brain or the spine, then almost instant incapacitation occurs and it does not seem to matter just how big the hole is. On the other hand if the hole is in the vital organs of the heart / lungs / aorta / liver and so on, then incapacitation only occurs psychologically ( which we can’t count on because of the mental condition of the subject) or by a loss of blood pressure and thus the flow of oxygen to the brain ( this is physiological ). Even a good hit with a large bullet can take 15 seconds to achieve this. What is clear is that the bigger the hole the better. Bigger holes let in more air and let out more blood. An exit hole is a big help but there is the subject of endangering bystanders on the other side of the target to consider.

There are those who feel that the "temporary stretch cavity" causes by some higher velocity pistol bullets has a bearing on incapacitation. Most of the true experts in this field, from the International Wound Ballistics Association, to a few individual theorist tend to debunk this since this property does not create any permanent damage nor cause a disruption of blood flow. Some rifle bullets do operate with a sufficient "stretch" that the elasticity of certain organs actually become torn in the process, but this then becomes a permanent cavity and is not what we are talking about. Better to think of your bullet as a drill bit. It will drill "this" size hole "this" deep.

Expanding bullets, at least those that actually do expand, of course drill a bigger hole. This is a good thing but if the expansion becomes fragmentation then the bullet may fail to penetrate to a vital blood carrying organ or vessel. this is the number one cause of "failures to stop" in rounds that were placed with precision. For this reason extremely light bullets for their caliber should be avoided. What does this mean. Roughly it means 9mm, 38 Spl and .357 magnums should have expanding bullets that weigh 135 to 140 grains or more, recognizing that getting too heavy means too slow to expand, .40 calibers should be in the 150 and over range and .44 and .45 should be in the 200+ range.

Again, this is far too complex a subject to be sufficiently covered in one little page. Dig deep for it is an important thing to know. Your prospects for survival are only as good as your bullet.