An Alternate Look at Handgun Stopping Power

[Prosser]

There might be something to be said for just sheer bullet weight, even at relatively slow velocity:
"Among other weapons, I had an extraordinary rifle that carried a half-pound percussion shell; this instrument of torture to the hunter was not sufficiently heavy for the weight of the projectile: it only weighted twenty pounds, thus with a charge of ten drachms [270 grains] of powder and a HALF-POUND shell, the recoil was so terrific, that I spun around like a weathercock in a hurricane. I really dreaded my own rifle, although I have been accustomed to heavy charges of powder and severe recoils for some years. None of my men could fire it, and it was looked upon as a species of awe, and it was name "Jenna-El-Mootfah" (Child of a Cannon) by the Arabs, which being a far too long of a name for practice, I christened it the "Baby", and the scream of this "Baby" loaded with a half-pound shell was always fatal. It was too severe, and I seldom fired it, but it is a curious fact that I never shot a fire with that rifle without bagging. The entire practice, during several years, was confined to about twenty shots. I was afraid to use it, but now and then as it was absolutely necessary, it was cleaned after months of staying loaded. On such occasions my men had the gratification of firing it, and the explosion was always accompanied by two men falling on their backs (one having propped up the shooter) and the "Baby" flying some yards behind them. This rifle was made by Holland & Holland, of Bond Street, and I could highly recommend it for the Goliath of Gath, but not for the men of A.D. 1866.[1]"

 

[JohnKSa]

But it is a valid analogy, because it is exactly the point I was trying to make. And before we hypothesize about the kind of injury that results from being struck by a very slow moving automobile when your body cannot move, I will tell you that I've had vehicles pin me at low speeds more than once when another idiot in the shop was careless. Didn't feel good, but minor bruising was the extent of my injuries.

Minor bruising is precisely what you'd expect from temporary cavity from a .45ACP. Remember you initially based the comparison on energy figures between the slow-moving car and the .45ACP.

I've never been shot, but I believe I can reasonably say that the effects would be much worse.

The effects almost certainly would be worse from being shot. That's because the car strike only approximates the expected level of blunt trauma which corresponds to the temporary cavity/energy effect. That isn't the only wounding mechanism, and is rarely the major factor in wounding the case of low velocity/low energy rounds like the .45ACP.

I maintain that the energy itself isn't the wounding mechanism, but how it is applied.

The amount of energy dissipated in the target medium is related to wounding on one level or another. You can't get away from that because it's more or less the definition of kinetic energy.

Similarly, it is not the energy that causes ballistic shock waves or temporary cavitation, but a combination of bullet size/shape and velocity.

First of all, saying a thing repeatedly does not make it true. Second, kinetic energy is a "combination of bullet weight and velocity" and the shape/size of the bullet is certainly a factor in how much energy is dissipated in the target medium.

What all this seems to be pointing to is that you don't like the term "kinetic energy" or "energy" but that you agree that if we call it something else it creates the same effects that are normally attributed to energy.

Saying that a higher energy round will cause more damage than a low energy round is a generally a true statement, but that is only because the high energy rounds are either driving bullets faster, driving bigger bullets, or both.

Yeah, since bigger bullets are heavier and energy is a function of bullet weight and bullet velocity what you're effectively saying is that:

"Saying that a higher energy round will cause more damage than a low energy round is a generally a true statement, but that is only because the high energy rounds have higher energy."

Why? Because blunt force trauma, no matter how powerful, will never be a gun shot wound.

That is true because a gun shot wound incorporates aspects of both blunt trauma and puncture wounding in varying amounts based on a number of variables.

So it's neither exclusively puncture or blunt trauma, but it combines the two. With rounds that don't dissipate much energy in the target medium there is very little of the blunt trauma aspect incorporated while one can go to the other extreme with some of the special purpose handgun rounds with almost explosive expansion which penetrate very little. They dump so much energy so fast that the puncture wound aspect of gunshot trauma is much reduced while they create more of a blunt trauma effect than is typically seen in similar caliber handgun rounds.

 

[MachIVshooter]

Minor bruising is precisely what you'd expect from temporary cavity from a .45ACP. Remember you initially based the comparison on energy figures between the slow-moving car and the .45ACP.

Yes, I remember very well.

The point I'm trying to make that is continually eluded via obfuscation is that "energy transfer" in and of itself is not what makes bullets lethal. That is why I drew the parallel; A car that hits someone at those low speeds and stops because their body has been pinned has now "transferred" 100% of it's kinetic energy to that body, just as that 400 ft/lb .45 ACP bullet did if it did not exit. Yet the effects are vastly different because:

That isn't the only wounding mechanism, and is rarely the major factor in wounding the case of low velocity/low energy rounds like the .45ACP.

Your words.

You wanna compare a "high-energy" round, like the .44 mag? OK, then instead of a 3,000 pound car, use a 7,000 pound truck. Guesss what? Even though we've increased the energy by more than double for both the handgun and the vehicle (now making it a "high energy" scenario), we still have vastly different effects from that 100% "energy transfer".

I've never argued that KE doesn't matter. Quite the opposite.

But saying that kinetic energy wounds is like saying torque causes a car to move. Neither one of them does a thing unless correctly applied. The KE must be used to cause the bullet to penetrate and expand, just as the engine's torque must be channeled through drivetrain to the tires and requires friction with the road to actually propel the vehicle. No, a bullet cannot wound without KE and a car cannot move without torque, but that does not make them the sole component of action/effect.

Similarly, a given amount of kinetic energy does not translate to a certain level of trauma, just as a particular amount of RWT does not equal a definitive ability to accelerate or tow. It's all about the application.

Yes, I like my car analogies. Sorry, it's just something that works most of the time.

 

[Loosedhorse]

That's funny, since I do believe there are some pretty magic numbers.

That's fine, although the interesting question becomes, why do you believe that?

I personally believe that there's something magic about a 500gr bullet travelling at least 2100fps for thick-skinned dangerous game. I have no "scientific" evidence for that belief, perhaps. Just the advice (with terrific general agreement, with a few of them bickering about the details...and one or two absolute heretics! ) of experienced experts, including their interpretations of occasional necropsy results.

Now, if someone hands me a 400 grain at 2350...that's fine. A 500 at 1500 fps? Well, now...

I've been talking hunting, but I think that the discussion of stopping dangerous game is similar to that of stopping human attack. Hunters talk about the ability of any given round to stop the change (generally, a CNS hit)...but also about the ability to "turn the charge": hit the animal in the chest with enough wallop that he decides he's had enough. Any Cape buffalo shot through the heart while charging you can still take you out of this world in a hurry, despite his wound...unless the shot has made him decide he's urgently needed elsewhere.

These magic numbers exist. Are they valid at all? And why does the discussion of the "turning the charge" magic numbers (or Taylor Knock Out values, for that matter) seems so much like the discussion of "stopping power"?

 

[Prosser]

There is something that happens to animals when they are hit with certain size projectiles, at certain velocities that are sometimes just weird.

All the hand gun hunters I know SWEAR that a .475 with a LFN hard cast bullet going 1350 fps is pretty much magical.
The classic instance was one guy ham shot a deer, going away. The bullet hit the ham, passed through the entire length of the deer, hitting nothing vital. The deer fell dead in it's tracks!

Another group SWEARS that 525 grain LFN hardcast are Thor's Hammer, if .510 and going at least 1100 fps.
Another group swears by 350 grains, .510 caliber, going at least 1350 fps.
Start to see a trend?

I'm NOT going to argue with their observations. Much as if for the last 100 years people have settled on 500 grains at 2150 fps, more or less, in .458, I will trust the 100 years, and hundreds of thousands of game shot, and observations, that it works.

With hunting rifles if the caliber doesn't work you have a very angry customer, an injured animal, and perhaps a few dead people. The end result is feedback that is going to get back to both Professional Hunters and rifle makers. What works is going to surface quickly in that market. Government intervention is in this case, in the interest of a clean quick kill. The result:
Minimum caliber is .375 H&H in many countries.
The Forest Service in Alaska suggested awhile back the following calibers for Bear protection:
.458 Win Mag, 375 H&H, and 12 gauge slugs, in that order, and depending on what you could shoot well.

Now when we talk about 'stopping power' we have a similar situation, but, we also don't have a simple market to correct the situation. In hunting after paying 100 grand for your elephant hunt, you aren't going to skimp on a rifle to take that elephant with.

What makes these discussions so frustrating is that it really is just as simple
with handgun hunting stopping power. If the market was determined by what works it would look considerably different. If the handgun stopping power issue was dealt with in a similar manner, holsters would start with .41 Magnums I suspect, and go up.

If we look at Greg's article, and we see just this one figure:
.44 magnum:
One-shot-stop % - 59%
.45 ACP
One-shot-stop % - 39%
9MM
One-shot-stop % - 34%

Shouldn't everyone be carrying .44's, at least?
On top of that, his numbers for the .44 Magnum are HIGHER then the one shot stops for rifles and shotguns: 58%.


However, as the thread I started about LEO departmental decisions shows,
and the FBI choice of weapons, despite Urey Patricks' recommendations,
there is a long laundry list of factors that are involved that undermine the simple choice of using the caliber that works most effectively, and, designing
a round for that caliber that does what it's supposed to.

Another part of this equation is the African minimum caliber requirements are designed to protect life above all. You can't shoot a 375 H&H, you don't hunt dangerous game. Doesn't matter if your black, white, latino, female, gay, whatever. Dangerous game doesn't care about your particular subgroup
in our society. EVERYONE fits into one category: FOOD.

If law enforcement standards were similar, we would have better shots, fewer bullets in the air, and less bad guys.

What I get out of Greg's article, besides the merits of the .44, are that service calibers are all being shot out of the wrong kind of guns. 9mm, .40,
.45, 380, are all incredibly effective, when, as this article points out, you make multiple hits on target. You want a cheap solution?
Mac 10's in .380, with the old shoulder holster rig. Or better, the .45 ACP version. A POUND of lead, easy to control, on target, in less then 2 seconds WILL do the job. Burst fire handguns should be matched with these rounds if these are the bean counters choices...

 

[JohnKSa]

The point I'm trying to make that is continually eluded via obfuscation is that "energy transfer" in and of itself is not what makes bullets lethal.

Given the right circumstances "energy transfer" in and of itself could be lethal. It's not particularly likely with handgun bullets for a number of reasons that have been rather thoroughly discussed on this thread, but it certainly could happen.

That said, the penetrative aspect of the bullet is almost certainly a more pertinent factor to lethality in the majority of handgun bullet wounds.

I've never argued that KE doesn't matter.

Well, maybe not precisely, but you've come pretty close a couple of times.

Similarly, it is not the energy that causes ballistic shock waves or temporary cavitation,

Energy transfer is a big fat myth.

But at any rate, we're in agreement now. It does matter, it does cause temporary cavitation and in certain circumstances it can be transferred to the target medium in such a way as to cause significant wounding.

...a bullet cannot wound without KE and a car cannot move without torque, but that does not make them the sole component of action/effect.

I agree that KE is not the sole component of wounding/stopping power. However, that fact doesn't discount the importance of kinetic energy because it applies to every other single-number measure of stopping power/wounding. There is not now, (and in my opinion there never will be) a single number that can be accurately used as the sole measure of wounding or stopping power.

Kinetic energy is certainly not the whole story, but it is an important piece of the puzzle.

Shouldn't everyone be carrying .44's, at least?

No, if we are really only concerned about terminal performance we should all be carrying compact rifles or shotguns.

Pistols aren't carried because they're the pinnacle of stopping power, they're carried because they're convenient to carry. They're generally limited in power because people have to be able to shoot them and most people don't have the time or inclination (and many don't have the ability) to develop a reasonable level of proficiency with handguns that are suitable for hunting large dangerous game.

If law enforcement standards were similar, we would have better shots, fewer bullets in the air, and less bad guys.

No, if LE standards were similar we'd just have fewer LE.

Look, everybody knows that if you get into the supermagnum handguns or high-power rifles that you get superior performance but that alone isn't ever going to be enough to cause folks to flock to them in droves. There are other practical considerations that most folks aren't willing to ignore. That means that the .44 Magnum is never going to be a mainstream handgun self-defense cartridge even if someone publishes unassailable data tomorrow that proves incontrovertibly that anytime you fire a .44 Mag at someone they die of fright even if you miss them. The .44Mag is never going to take the place of the .380ACP--it's just not going to happen and 99% of the people reading this thread could list all the reasons why without even thinking hard.

Your points about what makes a handgun cartridge effective are right on target, but somewhere between there and making the connection as to why folks don't carry them you jump the track in a most spectacular fashion. Entertaining, but in the same way watching a superhero defeat the bad guys in a movie is entertaining. It's fun to watch but it's not like you're going to pick up any knowledge that's going to help you make any sort of practical progress in terms of dealing with real-world problems.

 

[Prosser]

Just some food for thought:
.475 Linebaugh loads:
325 grain Hornady XTP at 1626 fps.
Energy of 1,918 foot-pounds for a 325 grain bullet at 1630 fps.

How about a 500 caliber bullet at 2100 fps, 275 grains? 500 S&W.
Energy of 2,694 foot-pounds for a 275 grain bullet at 2100 fps.
The .500JRH can easily push them 1700 fps, in a manageable sized pistol.
Energy of 1,765 foot-pounds for a 275 grain bullet at 1700 fps.
The 454 Casull will push a 240 grain bullet at over 2000 fps.
Energy of 2,132 foot-pounds for a 240 grain bullet at 2000 fps.

.44 Magnum isn't far behind. Lee Jurras hunting load was a 185 grain at 1900 fps. Energy of 1,483 foot-pounds for a 185 grain bullet at 1900 fps.

Little recoil, change the bullet for the intended game. Guy shot nearly a million rounds. At one point, he could put 6 shots on a playing card at 100 yards.

Just to prove there are more then one way to kill a buffalo:
525 grain .510 bullet at 1350 fps, my .500 Maximum load:Energy of 2,125 foot-pounds for a 525 grain bullet at 1350 fps.

And, why the original owner sold the gun: 525's at 1650 fps:
Energy of 3,175 foot-pounds for a 525 grain bullet at 1650 fps.

So yes, I can carry a .510 caliber Sharps 45-120 on my hip.

By the way: Otto Candies took the Big 5 in Africa with the short version of my .500 Linebaugh Maximum. Was it a stunt? yes. But, the kenetic energy was higher then a 45-70 rifle.

I will say again: If departments approached LEO equipment like Big game hunters, we would have less lead in the air, fewer bad guys.

 

[ChCx2744]

I've seen inexperienced shooters not be able to hit the broadside of a mountain with a regular standard size 9mm handgun. I've then witnessed experienced shooters take that same gun and create jagged, bottlecap-sized holes in a target placed 15 yards away. If you KNOW how to shoot the gun well and keep it running properly, it becomes acceptable to compromise huge calibers for those that are smaller and lighter. In some cases, smaller and lighter may even be more accurate, therefore more effective than those enormous "one-shot-stoppers."

 

[Loosedhorse]

By the way: Otto Candies took the Big 5 in Africa with the short version of my .500 Linebaugh Maximum.

Larry Kelly, may he rest, was the first person to use a handgun to take the Big 5.

We're still waiting for the first hunter to end a wounded buffalo charge with a handgun!

(BTW, my preferred .475 Linebaugh load is 440gr at 1325fps...but so far that hasn't made it to Africa.)

 

[Prosser]

Some people shoot some weapons better then others, due to ergonomics, from day one. That's the problem with having such a variety of
people carrying: they have to pick a gun THEY shoot well, not what an instructor or someone else does. The design of the gun, loads picked for that caliber can be tailored to the shooter. My point has been that most of these choices are tailored to the lowest common denominator. I have large hands, and, I shoot a J frame .357 designed to conceal poorly. On the other hand I can drive tacks with a Detonics Combatmaster. Why should I be forced to carry a .357 I shoot upper body accurate at 7 yards? I have to carry it because some bean counter says that a 100 pound female officer must have a gun she can shoot well? Not to mention the stock trigger was 16 pounds, DA. I want to see ANYONE shoot that well.

Another consideration is most gun fights are over in 3-5 rounds. It would seem prudent to make sure that the few rounds you do get off are VERY effective, much like hunting big game.

LH: Stopping a wounded cape buffalo was done by Ross Seyfried, early 80's, IIRC. I was wondering if a Linebaugh custom Seville was REALLY the gun for me, 45 Colt, tight chambers, 6 shots. So, Linebaugh had me call Ross Seyfried. He spent nearly an hour telling the buffalo story.

Picture deleted due to change in copyright law from the 1909 time standard.

He got off 5 shots, with the buffalo charging from 25 yards, in less then two seconds. The loads: 345-360 grains, 27.5 grains of H110, for 1550 fps, and around 60K, would knock the cylinder on those old Sevilles out of time.
So, with a charging buffalo, stuck prone under razor sharp thorns, he shot, recovered from recoil, rotated the cylinder into proper alignment with his finger, cocked the gun and fired, 5 shots in under 2 seconds, and killed the buffalo, but not by much. Pretty much anyone else would have been dead.

Here's my gun: reblued by Jack Huntington, and he fixed the timing issue as well.


It now lives happily on a rancher's hip in Texas.

Back a bit on topic. Without custom grips, those loads were totally unshootable. Linebaugh sent me 12 rounds of the 345's that came out heavy at 360, and were supposed to do 1550 fps.
With the little stock grips on the Seville, they were unshootable. Jack Huntington put a set of custom grips on my gun, and it made all the difference in the world.

 

[Loosedhorse]

I stand happily corrected!

Sounds like his cylinder stop (I guess Ruger calls it a cylinder latch on its SA revolvers) was retracting under recoil, unlocking the cylinder. Happened to one of my revolvers until I replaced the spring.

Nevertheless, your counter-example seems to do more to prove my point than disprove it, regarding the advisability of handguns for dangerous game. Both you and Seyfried (who states that his handgun skills were beyond world-champion level) seem to agree that any other hunter in this situation would have been dead. Not a great recommendation for handguns as buffalo stoppers!

I'd love to get more details. For example, did he (because he chose to use this handgun) end up wounding the buffalo, and then have to deal with its charge (whereas with a rifle he could have cashiered it at once)? Did he choose to go after a buffalo that someone else had wounded, confident in his 5-shot revolver? Did he, in choosing a handgun, commit himself to such close approach that a charge resulted...one that could have been avoided with a longer range hunting gun?

A gun that stops a buffalo charge is very good, but one that prevents a buffalo charge may be better still! And here, it seems perhaps that only a unique (and likely irreproducible) combination of gun and shooter was necessary to stop a charging buffalo with a handgun...using all 5 shots.

Again, appreciate your pointing me toward the story, which I did not know about.

 

[Prosser]

LH: My pleasure.

The 345's, and sometimes the bullets came out heavier, at 360, were effective, but hardly stopping rounds. As the story explains, they penetrated 38" of buffalo, a lot for back then for any handgun. Come to think of it, that load was the heaviest penetration load available at the time, and, it wasn't one you could buy at the corner store.

Mr. Seyfrieds' next projects were the .475 Linebaugh, and shooting asian buffalo with it. No substitute for bullet weight, and, the 420's and 440's penetrate twice what the .45 Colt/Linebaugh loads did, with a geometrically more effective, larger .475 hole.

He also designed a bolt action rifle, the .585 Nyati, so everyone could have a cheap, bolt action level 4 stopper, much like his .577 double, but lighter,
and more beatable.

 

[bermo61]

Here is my theory...and its just a theory!

Whenever they do studies of stopping power the authors of the study try to isolate just one variable...caliber. Some go a little further and might include the various loads. But in any shooting there are far more variables involved...like shot placement, penetration, expansion of the bullet, etc. The human body is not homogeneous....it varies depending on what you hit...bone, muscle, fat, organ tissue, etc. A shot to the head may not penetrate the skull whereas a shot to the thigh might hit the femoral artery and be lethal.

I am a fan of the .380 acp for a number of reasons...but it is almost heresy to express these opinions in some gun circles. Here's my list.

1. A pistol is typically going to be a marginal stopper at best...not as some have said a "death ray." It is not a 12 guage loaded with slugs. Yes shots from pistols can be lethal, but they are not going to knock someone out of their shoes as they do in the movies!

2. A pistol left at home does no good....likewise a pistol that is big and or heavy is more likely to get left behind and provide zero security for it's owner.

3. Shot placement is crucial and larger calibers in smaller guns are harder to effect precision shot placement with. (I know some will argue they can shoot a .44 mag snubbie with great accuracy, but can you do it while you and your assailant are moving and they are shooting back? Maybe, but would a smaller gun make it easier?)

4. .380 acp guns tend to be very compact and light...meaning they will not get left behind and are thus good for observing the 1st rule of gunfighting...don't forget to bring a gun!

5. Most shootings take place at close range....under 5 yards...and are over in 3 shots or less....so high capacity situations with magnum loadings are not typically going to be necessary.

6. Over penetration creates a huge liability for a shooter so you probably don't want a really hot load even though gun magazine writers like them.

7. Using too large a caliber can create additional "ammunition" for a prosecuting attorney that will attempt to paint you as an "assasin" following a justified self defense shooting.

I think based on these thoughts the .380 is more than up to most tasks required of a handgun...and superior to most others. Also the ammo is smaller and lighter so you can carry more for the same amount of weight. About the only thing I don't care for is the expense of the ammunition....but I think all ammunition is overpriced these days! Is it the perfect caliber for someone who works on a 500 acre ranch dispatching varmints? Is it the prefect caliber for law enforcement or military applications? Would I use it as a back up for hunting big game? No, no, and hell no!!!! However for "urban self defense", I think it is an excellent choice.

 

[Shawn Dodson]

.380 acp guns tend to be very compact and light...meaning they will not get left behind and are thus good for observing the 1st rule of gunfighting...don't forget to bring a gun!

The first rule of a gunfight is - Don't get shot!
The second rule of a gunfight is - If you do get shot, drive-on and don't give up!

 

[JohnKSa]

I think based on these thoughts the .380 is more than up to most tasks required of a handgun...and superior to most others. Also the ammo is smaller and lighter so you can carry more for the same amount of weight.

That might be overstating a little bit.

It's generally agreed that 12" of penetration is the minimum acceptable and that expanding ammunition is definitely preferable for self-defense. The .380ACP has trouble making that minimum with expanding ammunition.

If you compare .380ACP ammo to 9mm, there's not much weight or size savings.

The advantage of the .380 is that guns in that caliber can be very small, light and compact and while the caliber definitely gives something up in terminal performance, it is close enough to the threshold of minimum performance that many feel they can overlook that negative factor.

I carry a .380 from time to time when nothing else I have is small enough to conceal under the circumstances. It's better than being without a gun, and better than being with an even smaller and less shootable gun in a less potent caliber, but I know it's a tradeoff when it comes to terminal performance compared to carrying something that will make the 12" penetration minimum with expanding ammo.

 

[lloveless]

In the study by GE .32 caliber did amazingly well, which everyone discounted. Think about who carries such a gun (I believe Seecamp was the first). Generally people who know its limitations, and was able to use it to great effect. In that context perhaps the data was correct? In other words: operator knowledge made the use of a smaller caliber more lethal.
ll

 

[mudriver]

It becomes very difficult to draw conclusions based on data that is heavily driven by human psychology. However, I drew a couple of conclusions based on my vast experience of concluding trends on less than complete analysis:

1. if a .25 can get a one stop shot over 40% then that leads me to conclude that somewhere around 40% of people stop when being shot /achieve a psychological stop regardless of caliber.
2. This may overstep the analysis but if 40% of people stop due to just being shot, and 40% of people shot with a .32 are not incapacitated, then the probability of 'stopping' power of a .32 due to wounding effects are likely at 20%?? If this logic holds (might need to look at this again) then a 9mm is 1.85 times more effective at stopping due to wounding effects than a .32.
3. I think in terms of relative effectiveness the failure to incapacitate is an interesting metric. I've always assumed that 80%+ 'situations' that I would encounter would end based on 'displaying' a firearm. Therefore comparing the .40% failure rate of a .32 vs. a 13% rate of a 9mm results in an actual 8% failure rate for a .32 vs. 2.6% for a 9mm. Therefore the failure rate of a .32 is 3 times higher than a 9mm.

Of course these are all relative numbers but those make sense to me.

 

[mljdeckard]

I will say that the .380 has come a long way. With modern defensive ammo, I wouldn't tell anyone not to carry it for THAT reason. However,

If you aren't disciplined enough to carry a gun because you think it's too big, that is entirely your fault. Don't blame the gun.

Shot placement is crucial no matter what gun you are using. A compact .380 has a shorter sight radius and less mass than bigger guns, making it harder to aim and shoot well. In any armed encounter with any gun, you are doing well to get shots in the 8 ring. Don't assume a compact .380 is easier.

You can't ASSUME that your first few shots will end the fight. You might only get one shot. You want to make it count no matter what bullet you are using.

There is no such thing as a cartridge that reduces the likelihood of over penetration and is still effective for defense. And even if there were, you don't know that all of your shots will hit. There is ALWAYS a risk of hitting something behind the target.

The Fish case was influenced by the cartridge used. However, if a prosecutor has a case so thin he is trying to use that against you, he will try to use anything against you. Your gun was too big. Your gun was too little. You used cop bullets, so you want to be a cop. You should have used cop bullets to be responsible. All that stuff is FAR down the list for realistic risk of actual legal harm. I am MUCH more concerned about surviving to face the trial.

 

[Skribs]

As has probably been mentioned in this thread, and definitely in others on this particular study, is that there are a lot of fallacies involved - especially when you combine various cartridges together (i.e. "shotgun" could be a .410 with birdshot or a 12-gauge with #1 buck) and you don't have all the facts. In fact, any of these "one-shot stop" studies have the same problem in that they ignore the large number of other factors, including what organs were hit and whether the target stopped voluntarily or involuntarily.

I am of the belief that a physiological stop can only be reliably achieved by causing damage to CNS, the heart, or any of the major blood vessels between them. Even then it's not gauranteed, but with those particular hits you will quickly prevent the body from functioning. I also believe that until we have a computer simulation which runs millions of iterations (changing only one factor at a time), we won't have a very good description of what each caliber does.

My perspective is that the difference between a 9mm and a .45 ACP round is what the .45 will hit that the 9 doesn't. Let's take the heart for example, and assume 3.5" circle to represent the heart (quick and dirty math here), 0.65" circle to represent the 9mm, and 0.77" circle to represent the .45 (both expanded).
This means that the 9mm will at least nick the heart anywhere within a 4.15" circle (13.52 sq"), and the .45 in a 4.27" circle (14.31 sq").

This means there is only 5.8% wider surface area where the .45 will hit that vital organ that the 9 missed. Take it to a practical application and assume you're hitting a 6" circle (28.26 sq"), and you have 47.8% chance with the 9, 50.6% with the .45. You can see how the wider the circle, the smaller the difference in whether or not you're likely to hit a vital with a bigger bullet. If you shrink that circle small enough, it really doesn't matter.

What this means, to me, is that I guess "training" might be the answer to "9 vs. .45" up until someone is proficient enough to hit a fairly small target. If you figure that the gap between the two closes as the percentages decrease, training will be what will help.

Still, I'm waiting for computer simulations to be done. I'm not really convinced that 5% wider hit radius is enough for me to consider going .45 over 9. In stats, we learned that 5% is statistically significant, but at the cost of approximately 30% ammunition in the magazine (with the model I'm looking at) and the literal cost of ammo (for practice) I'm not sure if I can justify the wider bullet.

 

[Tcruse]

"You mentioned that the 9mm was most likely faster to shoot than a .38 revolver. That really depends on the shooter since Edward ('Ed') McGivern could shoot 5 shots in .4 seconds, and we regularly demonstrated shooting six shots in under a second with duty ammo for our classes with a six gun. I don't know what the cyclic rate of a Glock-17 is, but the 1911 was 5 shots max per second, according to the manuals.
"
Published rate for Glock 18 is 1200 rounds per minute. (Gen 4 Glock 17s were tested in full auto mode to prove frame would not crack)

 

[481]

I'm not really convinced that 5% wider hit radius is enough for me to consider going .45 over 9. In stats, we learned that 5% is statistically significant, but at the cost of approximately 30% ammunition in the magazine (with the model I'm looking at) and the literal cost of ammo (for practice) I'm not sure if I can justify the wider bullet.

Given that the .45 will miss the same structure that the 9mm would unless it passes within 1.25mm of where the 9mm would, the increase in capacity provided by the 9mm is the better option. In other words, if the .45 passes farther than an additional 1.25mm from whatever needs to be hit, it also misses the mark. Not much of an advantage there.

 

[JohnKSa]

This means there is only 5.8% wider surface area where the .45 will hit that vital organ that the 9 missed. Take it to a practical application and assume you're hitting a 6" circle (28.26 sq"), and you have 47.8% chance with the 9, 50.6% with the .45.

The 5.8% wider surface area can't be converted directly to a probability without making some assumptions.

The first assumption is that the distribution of the bullets is uniform, i.e. that the bullets are just as likely to hit one place on the target as another. It may or may not be a reasonable assumption, but it makes the problem tractable so let's go with it for now.

The second, and this one is quite problematic, is that the scenario assumes that the entire surface of the target is a circle of 4.27" radius.

In reality, a human torso makes up a much larger target than that, and the bullets could strike anywhere on the target (or even miss, for that matter). If you assume that the bullet hits are distritubed uniformly over a surface area that is roughly the size of a human torso, then the chances of hitting the heart with one caliber, vs. the other goes way down.

To see what changes I increased the target area to the size of a human torso, I set up a monte carlo simulation with your parameters, (3.5" heart, 0.77" .45 bullet, 0.65" 9mm bullet) but with a target area roughly the size of a human torso. It turns out that the times that the .45 bullet will hit the heart when the 9mm misses account for about 0.18% of the trials.

That still doesn't tell the whole story because:

1. One can, as already mentioned, miss the entire target. That would decrease the probability difference even further.
2. There's still the matter of our first assumption (uniform distribution) which we didn't try to justify. If we went with a weighted distribution, it would likely increase the probability difference by biasing the distribution somewhat toward the center of the target, but not by much, in my opinion, given the relatively low hit rates encountered in gunfights.
3. There are other structures in the torso that could cause rapid incapacitation if struck. That means the scenario really should be run with more than one target that could be hit/missed. That drives the complexity up to the point that it's a pain to work with.

However, even with those problems, I think that the numbers give us a very rough idea of what kind of benefit one can expect from depending on a larger bullet to make a hit when a smaller one might miss.

 

[Skribs]

John, maybe it wasn't clear from my ramblings, but that's why I took the example of a 6" accuracy benchmark to use. If you take a 12" accuracy benchmark, then you'd have 12% and 12.7% chance to hit, etc.

I understand that the limitations of this type of analysis are that it assumes uniform penetration and bullet path, and that it oversimplifies the issue. However, that oversimplification is to provide a quick-and-dirty method of showing what the actual difference is. As you have a wider radius for potential impacts, the difference between the 9 and the .45 drops very quickly, in that both are very unlikely to hit the vital part of the target.

Interesting fact, if you take 12.7 / 12, you still have the 5.8% difference between the two.

Given that the .45 will miss the same structure that the 9mm would unless it passes within 1.25mm of where the 9mm would, the increase in capacity provided by the 9mm is the better option. In other words, if the .45 passes farther than an additional 1.25mm from whatever needs to be hit, it also misses the mark. Not much of an advantage there.

I've said this before, but this puts it into a 2D perspective instead of a 1D perspective what the difference is. Assuming similar penetration (which, for the most part, is going to be only 1" or less longer in the .45 using standard SD ammo), and you have the same model in 2D as you do in 3D.

Like I said, it rounds some stuff off (literally, rounding the shape of the heart) and it makes a lot of assumptions, but it shows how close the two are.

3. There are other structures in the torso that could cause rapid incapacitation if struck. That means the scenario really should be run with more than one target that could be hit/missed. That drives the complexity up to the point that it's a pain to work with.

This depends largely on the part of the target, but unless it's a CNS hit, I don't believe anything else will stop an attack fast enough to safely protect the defensive shooter, unless you simply put a LOT of lead into the target. With the heart damaged, you're talking of only a few seconds, but with damage to a single lung (or even both) or a severed artery (that doesn't go directly to the brain) it would take more than a few seconds to starve the brain of oxygenated blood.

 

[JohnKSa]

John, maybe it wasn't clear from my ramblings, but that's why I took the example of a 6" accuracy benchmark to use. If you take a 12" accuracy benchmark, then you'd have 12% and 12.7% chance to hit, etc.

Ok, got it.

Still, given that it's fairly common to see people missing entire persons at a rate of 60% or better in actual gunfights, I think that even using a 12" accuracy benchmark exaggerates the probability difference significantly.

I used the surface area of an entire human torso, and that still exaggerates the difference if you consider that it assumes ALL the bullets hit the torso--and we know that doesn't happen in real-world gunfights. It's not even close.

I didn't quite follow what you were saying with the accuracy benchmark, what I was primarily responding to was your mention of 5% in your closing statement as if it were a probability ("In stats, we learned that 5% is statistically significant,").

5% shouldn't be seen as a probabilty that relates to the situation. Even the still over-optimistic scenario (assuming that a person never misses his opponent's torso in a gunfight) provides a probability difference less than a fifth of a percent. We're talking one additional hit to the "heart" out of 500+ shots taken.

This depends largely on the part of the target, but unless it's a CNS hit, I don't believe anything else will stop an attack fast enough to safely protect the defensive shooter, unless you simply put a LOT of lead into the target.

There are probably some very large blood vessels that would cause rapid incapacitation if they were damaged badly, but I agree that there aren't that many things that will shut an attacker down rapidly.

I wasn't disagreeing with you, as much as I was trying to thoroughly explain the caveats that govern the calculation results I provided.

The bigger point is that even if one were to try to make the scenario realistic by adding more target structures, or adding a weighted distribution, etc., the fact remains that the benefit provided by the larger bullet (in terms of probability of making a hit) is not going to be significant if we keep the numbers remotely practical.

 

[Skribs]

The fact that the best case scenario would be a 5.8% difference, but also if you compare one subset of accuracies to the other (i.e. 12.7 / 12) it's still got 5.8% higher chance. That number will remain constant unless the area is smaller than the larger bullet. But yes, within a 12" range, you woul dhave a 0.7% difference between the two.

There are probably some very large blood vessels that would cause rapid incapacitation if they were damaged badly, but I agree that there aren't that many things that will shut an attacker down rapidly.

Yeah, but I'm pretty sure we're talking more than 30 seconds, barring a "voluntary" response, such as shock or fainting. Not that the indivual would choose to faint, but that the body would still be capable of returning fire.

Maybe benchmark wasn't the right word. More like, I needed to set a surface area that one might hit within in order to say "within this range of shots, you are X% more likely to hit with the bigger bullet" (and then look using subtraction and division). If you say only 30% of the shots hit the torso, and then go from there, then you take 0.3*(SA-caliber / SA-torso) and you have an even smaller difference. (But still the 5.8% comparison).

I'd still like to see a computer simulation, but I think this is definitely causing me to lean towards the 9.

ETA: The benchmark was also to show how being more accurate means that your choice in caliber means more. At a 12" circle, there's 0.7% difference, but at a 6" circle there's a 2.8% difference. Which means that the closer you are to hitting the center, the more important gear selection is.