You just helped me make up my mind. A buddy of mine has a S&W .40. It's a sweet shooting little pistol. But I'm going to look for a 10mm. I like power. I like loading my rounds a little hotter than factory ammo. This weekend, my buddy and I shot up more than 100 rounds of .44 mag hotloads (among other things). These were 21.5 grains of H110 behind 240g bullets. Definitely had some scuffed places on the hand after that.
Perhaps you could try the log of the velocity in the formula. While that woudn't actually change the results, it would squeeze the velocity number in the scale.
No need to constrain it to base 10 either, a natural log or a base 2 log may be more appropriate.
Just a thought,
-Mark
I think Wadcutter is a physicist. He might be able to help out here. As usual, a great and thorough post.
Now I have no where near the level of math or engineering knowledge of Chris, but I have an idea here, hopefully I can articulate it while doing 5 other things at work right now.
I think that Chris and Toad are both on the right track in the method they are producing numbers to relate to killing power as I understand it.
But, we need to look at something else here, the object of the bullets affection.
This is where it gets tricky, we are talking about killing power as it relates to humans. Every human is different, but there are some consistancies.
The density and consistancy of human flesh will probobally be less consistant than with other species on this earth. We vary in weight and fitness more than any other species, so a different mamal might be better for this theory.
As long as we have an agreable formula for the killing power of the bullet, like Chris's we move on to the effects of said bullet in flesh. This is where I agree with Chris's findings that velocity tends to be the most important of the three 'power factors' calibur, weight and velocity. Velocity as it would seen to me would have the biggest negative effect on flesh. Flesh will alwayse slow a bullet down, alwayse. And energy never ceases to exist, just changes form.
The energy of the bullet, velocity being the biggest contributor of energy is what does the damage. The bullet slows down and dumps that enery into the tissue, which has to dissipate this energy now and does so by fragmenting and tearing. The more of this fragmenting and tearing, the harder it is for the body to recover.
So should the next step be putting numbers to flesh density, tensil strength, the damage signatures of flesh, then a formula which combines the flesh damage formula, and the 'killing power' formula to get a more accurate look at the effects of a cirtain projectile.
Side note: i see this as being a huge pain in the ass to get even remotely accurate given that different locations on the body, muscle tissue, bone density, and organ type and density will all respond differently from one another. Unfortunately I don't have the physics and math abilities to run with this like I would like. Just the ability to theorize.
Looking for 200gn xtp, and 220gn LFN load data for 10mm
where did you get this data:
200grains at 1270 fps 715 ftlbs
220 grains at 1335 fps 792 ftlbs
Steve, I honestly dont remember. It was off a handloading web site.
I think that beyond the raw numbers you have to account for penetration with a give cartridge and bullet type. Lets say you have a .44 mag moving at 1350fps and 971 ftlbs; if the bullet passes through the body how much of that energy is dumped into the target and how much is retained by the bullet as it continues in flight? If the round misses any bone and only deposits, for the sake of argument, 400 – 500 ftlbs in the target how effective is it? I think that is one of the reasons the .45 ACP is a proven man stopper. Its low speed and limited penetration (when compared to magnums) allow it to shed most of its remaining energy into what ever you are shooting at.
Pertinax, that's generally how I see it as well. THis also accounts for the effectiveness of the .357. It's the "most powerful" cahmbering likely to expend all it's energy in the target without exiting. Anything "more powerful" is HIGHLY likely to go through and through; and while it will do lots of damage doing so, that level of power has undesireable tradeoffs.
i an just a gunsmithing student, veteran, handloader, hunter and target shooter but if you take a look at the P.O. Ackly books,(i think it's the first one) the tests done by the army using goats as test media and the post death investigation by the dr. should show you what you are looking for as far as 2legged dangerous game.
also a 10mm fan i think the 180gr xtp is accurate and built for the real world
Chris has excellent reasoning here- but may I nitpick one small statement? The .454 casull vs .500 s&w statement assumes a need for the deeper penetration from the casull, doesn't it? Uh, maybe after penetrating the neighbor's living room wall after going through the perp breaking into your house at 4 AM? Why wouldn't the .500's larger diameter (lower sectional density) deliver its energy over a shorter duration potentially not be to its advantage in this case? Isn't shock pulse more significant than sheer (over) penetration here? Energy left over after it passes through the target accomplishes what? With big bears this will be a different matter entirely, of course. Think I'd prefer a robustly loaded 45-70 over any handgun in that situation.
Anyhow, Chris's line of thinking seems absolutely right on, otherwise. I appreciate his candor about how difficult it is to quantify killing power mathmatically. It is indeed a complex topic as he rightly points out.
Let's not forget that there's currently no such thing as a +P .40 round.
Other than that -- a simple mathematical calculation tells us that a larger caliber has significantly more surface area to create wounds. At pistol-round velocities, this is very important.
Uhhh, there isn't?
Why do I have a dozen boxes of +p (and more than plus P from corbon, and triton) on my shelf?
old thread, i know - but i couldn't help mentioning this...
i haven't done the math to calculate exactly what it is, but there is definitely a velocity threshold at which any formula used to calculate the effective stopping power of a pistol cartridge becomes inapplicable to a higher velocity projectile, such as a rifle bullet. there is a point at which a ballistic shockwave is generated within a (mostly) liquid body of certain density (i.e. flesh), which creates a massive amount of secondary trauma. this shockwave effect accounts for the fact that a .30 caliber bullet travelling at 2700 fps generates _massively_ more stopping power (i.e. ballistic trauma) than the same weight and caliber bullet travelling at 1900 fps.
therefore, it only makes sense to determine this threshold, and then to have two different formulas to calculate the effective stopping power of rifle bullets vs. handgun bullets (or, more specifically, bullets travelling below the velocity threshold and those above it).
The DPF formula you're using there is actually almost identical to the late Col. Hatcher's CSF (Comparative Stopping Power) factor. The one difference is that the Mad Ogre's DPF makes no allowance for bullet type, while Hatcher included a bullet type factor - if memory serves, it was something like 0.7 for FMJ, 0.9 for a soft-point, 1.0 for a flat-point, 1.1 for wadcutters, 1.25 for hollowpoints. (None of the advanced controlled-expansion rounds of today were available then, of course.)
By figuring out reasonable shape factors for controlled-expansion rounds and for spitzer-point FMJ rifle rounds, this might perhaps be usefully updated both to make it more predictive of modern high-performance bullets, and to make it more useful for comparing rifles to pistols.
Have you read Fackler's response to the FBI's request ("Handgun wound effectivness")? Having killed quite a number of large animals (hunting in AK and lower 4
I am convinced that the best bullet has a large frontal area and most of the time makes two holes. Frontal area with adequate penetration (sounds like Elmer K.?). Fackler has probably surveyed as many wounds in humans as anyone alive and he came to the same conclusion. Ross Seyfried has also opined from that camp. We cannot assume that the shot we get to take is the shot we want. Bones, cloth, hardware, and concealment have a nasty habit of getting in our path. I see no conflict in equating a man you have to kill with a dangerous animal you have to kill and that is why I carried the S&W 1076 on the street. If the bullet strikes bone I want it to break him down and give myself another shot. Few innocent people have ever been harmed from over penetration (not talking about missed rounds) while many peace officers have been killed for the lack of it. Fackler said you cannot equate physics on paper to trauma with a handgun in the same manner as high powered rifle...tissue damage from "high speed" hand gun rounds through "shocking power" or "energy expended" just doesn't exist at the lower handgun velocities. Handgun bullets (especially round nose) tend to push tissue aside and you simply don't see the trauma associated with high power rounds. Frontal area and penetration are almost all you get, which is why Fackler recommended .40 or greater. Now having said that I will admit that handgun bullets have come a long way from the old soft points we used to have to carry (unless we cast our own and of course that wouldn't be allowed in law enforcement). I have performed my own tests on penetration and effectiveness when we have had to slaughter cattle and have found that a hard cast bullet with a large flat frontal area,in a .357 or larger handgun (I own .357, 10mm, .44mag,.45 auto), still out-penetrates and kills better than most of our new technology if I have to shoot through thick hide and bone (Ross told me that I would get even better results if I would heat treat my cast bullets). I realize that this opinion was not solicited and is perhaps the minority view. Thanks for an interesting article and the chance to respond.
I'm going to second Dale's opinion.
What the bullet actually does in flesh is the important thing. Bullet diameter, velocity and mass are all important, but they all interact with bullet design in interesting ways.
Just as an example, higher velocity tends to cause hollow point ammunition to mushroom wider and earlier - causing lower penetration. If you buy the IWBA 12-18 inch penetration guidelines, increased bullet velocity may lead to decreased lethality.
This sensitivity to bullet construction is the main reason why creating a formula for bullet effectiveness strikes me as difficult at best.
just remember chris, the 5.56mm bullet tumbles and creates hydrostatic shock because of its velocity (LMFAO!!! joking 
my personal opinion is that the US military (and NATO) should scrap their current line of small arms calibers and adopt ones better for human targets. Based off of my opinion:
Handgun: 45 ACP or super
Rifle: 6.5 or 6.8
interestingly enough, the British, while developing a replacement for the lee-enfield line of rifles, sought to develop and field a 270 size cartridge (similar to the 6.5 or 6.8 currently being tested 60 years later in afghanistan) for their new rifle. The US forced NATO standardization and they adopted the 308 as the standard cartridge and the british adopted a inch-version of the FAL (L1A1 SLR i believe). They were far ahead of their time. the US would later adopt the 5.56 only to look into 270 size cartridges in the 21st century. interesting....it just appalls me that the british, who are known for their adept weapons designs, adopted the abysmal SA80 (I hate bullpups).
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