Tons of good info – and links that I missed – don’t know how.
A long time instructor and student, I feel I have a pretty good understanding of ballistics. Here’s what brought me to my original post though and I realize that finding a concrete answer in a subject area marked by a combination of theory, science, and case study is an uphill battle.
I recently obtained a copy of my own police report wherein I shot a bad guy with a .223 caliber M-4 carbine at about 10 yards. He was at a very slight angle to me. The single Federal 55 grain hollow point penetrated the sternum and center-punched the heart. I am aware that a person can theoretically continue for up to 15 seconds or so with even such a devastating wound. However, in my case I can say that without a doubt life left the body while he was still fully erect. I have seen a lot of death. There was no delay. Eyes, instantaneously limp body, a literal sack of potatoes if you will. I have even considered the psychological effects of being shot and thinking you should fall but let me say this, he wasn’t thinking anything the moment that round hit his chest.
So what the heck was it? Blood loss couldn’t have been fast enough. 15 seconds hadn’t elapsed. Central nervous system disruption is a maybe.
While I am very familiar with temporary wound channels, permanent wound channels, the effects of blood loss, destroying vital organs, the theory of hydrostatic shock, and more, I have endeavored to put it all into a concrete “why.” Things such as the .357 having seemingly a greater ability to stop a threat, all being equal, than the .38. They can have the same bullet weight and often penetrate to nearly the same depths. The .357, having a higher velocity, has a much higher foot/pounds of energy result. What is it about the greater velocity and foot/pounds that makes it a better stopper? A lot of test data, including referenced graphs, seems to conclude that they are about the same but I would say in reality it’s the .357.
Both rounds (or many others you could compare) will do the things necessary to stop – destroy vital organs, blood loss, etc. Basically what it comes down to is, all else being equal, why is kinetic energy, foot/pounds energy, or something else entirely, so important? That is why the “force” and “energy” combination presented in the original write-up was appealing.
For reference, and I am sure not boasting for the experiences have been less than pleasant, but between the military and police work I’ve had a few shootings with the handgun and long gun. Those hit with rounds from the handgun didn’t seem to react as quickly and this makes sense to me, but that would seem to discount blood loss, organ damage, etc., to some extent because rifle or handgun, each caused significant damage and blood loss while the rounds all achieved adequate penetration. "Acceleration" is possibly a variable between the rounds but I'm not sure how that plays outside of the force equation. The graphs depicting kinetic energy are interesting but don't seem to indicate a large difference between calibers that are traditionally thought of as having a large disparity.
So, force, kinetic energy, momentum, what is it? Though it is much criticized, “hydrostatic shock,” in part contributed to the increased velocity of rifle rounds, seems to be consistent with my personal results, which taken in perspective I admit is a very small sampling.
I know, an age old discussion. All of the above I guess. But my intellectual side beckons for clarity.
