Firearm Stopping Power…a different perspective.

[Deja vu]

Id like to see them separate them out more. Combining things like a 410 shot gun and a 12ga make the shot gun section less accurate. Even putting semi similar rounds like the 357 sig and 357 magnum together make the data less accurate.

[tipoc]

There are a good many branches of science that do not require that the results of the object of study be replicated in a lab. Astronomy, geology, the study of tornadoes, the movement of tectonic plates and a good deal more. What they do rely on is accurate observation and careful attention to the details. There is not enough of that in this short article by Ellifritz to qualify it as a "study". It is an opinion piece with some data added (that data may or may not be accurate we have no way of knowing) to back up the opinions.

Look at one point he makes here, just as an example of what I mean...

The average number of rounds until incapacitation was also remarkably similar between calibers. All the common defensive calibers required around 2 rounds on average to incapacitate.

How does he know this? He provides us with no information that shows that it was the second, and not the first or third round, that "incapacitated" the person who was shot. If the person was shot with a rapid double tap to the chest how does Ellifritz know that it was the second round and not the first that did the actual "incapacitating"? Yet he says here that for sure it took two rounds "on average" to incapacitate.

The entire article is filled with a number of such statements that just do not show signs of accurate observation. For example; he makes no distinction between bullet type. Ball, jhp, LSWC, etc. all the same to him. No difference either in bullet weight. He combines all types shotguns together and all centerfire rifles together. He combines the 22short, long and lr together. He tosses carelessly the 357 Sig and 357 Magnum into one pot. etc., etc.

As for the rest will you really feel better armed with a gun carrying 32 acp or 380acp than a 40S&W or a 45acp? According to Ellifritz's figures the 32acp has a better record than the 45acp or the 44 Magnum. This must be true of course because he also shows that any round from a .22 short/long/ or long rifle is a better stopper than the 45acp.

tipoc

[C0untZer0]

I think there is information in the data, but it is going to take people who are skilled scientists to make sense of it.

I also believe it will take money to do that, and I don't think anyone right now is motivated to fund an actual study of the data.

Neither weapons nor ammunition manufacturers would fund a study because there is no profit in it. Is Winchester 100% sure that their brand of ammo is going to “outperform” Federal, Remington, Cor-Bon and all others… each and every time in all tests? Probably not, and the same can be said for Remington and Federal. Plus I don’t think these companies have the deep pockets to fund a study. If their brand of ammo did prove superior - could they sell enough "Golden Talon Super Stopper" rounds to pay for the study? Probably not...

Then that leaves some organization – like a very large law enforcement agency or association to fund some kind of study of the data.

Unfortunately, the LEA with the deepest pockets and most money available for this sort of thing already did a study. The FBI decided that useful data could be gathered by analyzing bullet performance in calibrated ordinance gelatin, and that there was a valid statistical correlation between trajectory, penetration and expansion of a projectile in gelatin and effectiveness against human beings.

I think at this point – for the FBI to fund additional research into determining bullet effectiveness could be fairly characterized as a waste of tax payer money. The same could be said of any law enforcement agency. The obvious answer to their request for money to study the data would be “The FBI already did that work. Why don’t you use what they use? It’s obviously working for the FBI.”

Maybe I’m missing something but it doesn’t seem like there is any likely source of funding for examining the data.

In all cases, it takes money to go through the data with scientific tools and methodologies. However, there certainly is money to be made by anyone who can haphazardly slap categories on this data and opine about it in a book or magazine. Failing that – they can start their own blog or website. Unfortunately, I don’t think the shooting community is well served by people like Greg Ellifritz, or Evan Marshall and Ed Sanow… or the next Greg Ellifritz…

You still hear the erroneous ideas kicking around in all the forums today “knock-down power”, “stopping power”, “Success rate”, “one-shot-stop”. I can Google an ammunition round and in 5 minutes find some blog or website that will have a long list of ammunition calibers and brands with a percentage next to them that says “Street Success Percentage” So, the danger is that the original faulty analysis that led to all of this just gets repeated as fact and people believe it nearly as such. I think you’d have to work in a gun store to see the effect it has on the general public and their buying decision, although I think we see it here on the forum to some extent when someone joins and says “Buying my first gun.” We hear some of the same stuff – guys who are looking to buy this that or the other because: “It’s got proven stopping power”, or this round has the highest “street success rate” (hopefully if you ever have to use it you’ll be on a street and not in a building). There probably is a very good decision process for making your first handgun purchase, and it’s been talked about on this forum - So first time gun buyers should take some classes, educate themselves about different firearms, learn about calibers, rent a whole lot of different firearms and see what they like, what they don’t like and why… But I think few people do that. I think it’s more likely that they Google “Best gun” And “most powerful gun” and they go from there…

Thankfully, major law enforcement agencies have stopped listening to the uninformed amateur analysis of shootings conducted by Evan Marshall, Ed Sanow, and others – including this Greg Ellifritz. I think a lot of agencies rely on the previous work of the FBI, but even when they don’t simply choose what the FBI chose - for most agencies now, they rely on the same methods, and because of that they rely on the opinions of degreed experts in the field. The law enforcement agencies have been putting more stock in the advice of people like Dr. Gary Roberts and Dr. Martin Fackler.

I don’t think this is going to change for a very long time.

There is a thread on here about “The Future of .40 cal in Law Enforcement” or something like that. I personally think that as time goes by, the .40 S&W is proving to be a “good” handgun round for LE. Unless there is some major event that challenges that. .40 is here to stay.

If you look at the 1986 Miami shootout – that was a pivotal event that led to funding for a major study of ballistics and handgun effectiveness, and resulted in a major paradigm shift for the majority of law enforcement agencies in the U.S.

I’m saying all this just to say that given this long history, and the seriousness of it – law enforcement agencies are not going to listen to people like Ellifritz.

[BGutzman]

What none of this data gives you is the skill of the shooter at the particular moment in time. For example body shots, its ok to use this but without breaking it down a little more the body outside of the head covers a wide ground.

So what if it happens the guys with the 380's practice more often than the guys with the 9mm (pick any round you choose) or the higher recoil of the 9mm equals less accuracy under stress. It could be true, but I have no way to know for sure.

Then again the guys carrying the 44 Magnums with much higher recoil seemed to have fared the best so maybe we all now just need to step up to a more powerful gun.

We can never get to a reasonable bottom line without more specific information and with today’s technology there is certainly the means to do digital or corpse based research.

The only other reasonable measure I can think is to use physics but that rapidly ticks off the guys that like the smaller calibers as light and fast eventually loses to heavy and fast. Yet again in the final analysis it has to be noted that even a 17 HMR can be lethal and a 500 Magnum can surely miss like any other weapon.

Keeping safety in mind we also have to think about penetration and over penetration.

The bottom line is certainly if we could shoot two or more different calibers on the exact same spot (with the path through body remaining the same) on the exact same animal (if such a thing were ever possible) then certainly some rounds are going to be shown to be more effective than others.

But sake of social graces we all try to pretend that they are equally effective due to modern super ammo.

The problem with the super ammo theory is and always has been is that all the guns have super ammo available or you can hand load it to this point. However each caliber is designed to work within a certain specification and the fact is some rounds are simply more energetic and heavier than others and thus they take more mass to stop them.

You can certainly take life with any gun but don’t kid yourself that a 380 has the same potential for lethality as a 500 magnum if the two are shot exactly the same on exactly the same target. The end result of both rounds could be the same but the amount of energy and destruction will be dictated by the physics involved and not someones dream that a particular gun was deadly based off someone likeing it.

[MrAcheson]

9 ball you seem to have a good grasp on the calculations but are failing with the practical application.
penatration is a factor of stopping the foward momentum of the projectile.

Not really, no. His grasp of calculations seem quite shaky. Momentum must be conserved. All forms of energy must be conserved as whole, but mechanical energy does not have to be conserved by itself. That bullet kinetic energy could, for instance, be converted to heat instead. The 44 magnum bullet used in 9ball's illustration would heat an 8oz cup of coffee up about 4 degrees F if completely converted to heat. That's not very much, is it?

One of the first rules of studying collisions and impacts is that you don't use energy unless the collision is perfectly elastic, you use momentum. Shooting someone with a bullet is not a perfectly elastic collision. So this equation is an inappropriate simplification:

F_resistance * x_penetration = Energy

It's also inappropriate because F-resistance is actually based on the drag equation which is also function of velocity squared just like kinetic energy. F-resistance is essentially proportional to kinetic energy so increasing kinetic energy doesn't buy you as much as you'd think. This is why when you want more penetration you generally switch to a heavier bullet. More mass that you have to slow down, less velocity that actually helps the bullet bleed energy off faster through drag.

And on a completely unrelated comment, the average shots to incapacitation is probably more closely related to a guns ammunition capacity than to bullet performance. Back when the police were moving to autoloaders, lots of people commented that the move was unnecessary because cops only fired an average of two shots in an engagement. The problem with that number is that cops almost never fired two shots in an engagement. They most often fired one shot (say 80% of the time) or completely emptied their revolver with 6 shots (say the other 20%). The average of those two behaviors worked out to two shots per engagement, but two shots wasn't actually a typical behavior.

This same behavior appears to be showing up in the rounds-to-incapacitation figures. Revolver and pocket pistol ammunition has lower average rounds. The rounds fired from high capacity service pistols like 9mm and 40 S&W have higher rounds-to-incapacitation averages. This is because the 9mm and 40 S&W guns have more shots and some shooters will make use of them to ensure that their targets are incapacitated.

[2damnold4this]

Some good posts on this thread

[Mello2u]

The more I think about case studies of shootings the more I come to realize that the major flaw in them is they that lack evidence and consideration of what the bullets did inside of the targets that did or did not incapacitate.

Consider hypothetical two shootings:
A) two bullets (choose you caliber .35" to .50") hit the target in the sternum at a 5 degree angle and proceeds to penetrate the left ventricle and lodge in left posterior latissimus dorsi after penetrating the 7th rib.
B) two bullets (choose you caliber .35" to .50") hit the target in the sternum at a 60 degree angle is partially deflected and proceeds to penetrate the left pectoralis major, runs outside the ribs and lodges under the skin at the margin of the left latissimus dorsi.

A) lots of hemorrhaging
B) little hemorrhaging
Bots hit center of mass, but what the bullet did or did not do inside of the target makes a huge difference.

As some here have noted such evidence would take considerable money. Such evidence would have to be uniformly gathered by specially trained trauma physicians who not only could care for the injured but also gather the data for later study; and gathered by Medical Examiners from those who died before medical treatment was administered. MRIs of the soft tissue damage and X-rays of the bone damage on all shootings to be considered would be useful in assessing what the bullet/s did inside of the target. Costly and time consuming.

[mavracer]

Not really, no. Momentum must be conserved.

yes really. when momentum = zero penatration will stop.conserving momentum in this case is a bad idea IMHO thats why I use hollow points.

If you actually study the external ballistics RELEVANT to wounds (since I doubt anybody has ever died from the heat energy off a bullet. Unless your using Willy Pete LOL) you will see exacticly how increased momentum affects penatration. Increasing kinetic energy without increasing momentum will have more of an affect on the size of the wound channel mostly temporary but it can have a affect on perminate wound channel from more rapid bullet expansion.

[603Country]

A good discussion, but it's getting bogged down. I think everyone was originally arguing over stopping power and over the contention in that article by the fellow that suggested that there wasn't much difference in various cartridges on stopping power. Seems obvious to me that he's very wrong. If we look at extremes, we have the 22 short at the low end and the 454 Casull (or something similar) at the high end. Said another way, that's a small slow bullet at the low end and a large fast bullet at the high end. I don't think any rational person believes that the small slow bullet is the equal of the big fast bullet when it comes to stopping power. With that logic established, everything else is in the middle, with the only determination to be made being where in that range does your favorite cartridge fit. Is a 9 mil equal to the 44 Mag? I sincerely doubt that it is. Is the 45 ACP equal to the 41 Mag? I doubt it. Does the 45 ACP outrank the 9 Mil? Well, that gets to be a tougher question, being that you have a small fast bullet versus a large slow bullet. Personally, I favor the large slow bullet, particularly if you use the same shape and design of the bullet (hardball). The same theory applies to rifle bullets. Would you expect the 220 Swift (55 grain bullet at almost 4000 fps) to be the game stopping equal of the 45-70 (large slow bullet) when it came to shooting an Elk? I don't think you would. So...ranking pistol cartridges should be as follows: Large fast bullet, then large slower bullet, then smaller fast bullet, then small slow bullet. Naturally, there will be some overlap in the middle of the range - say 9 Mil versus 357 Mag.

[MLeake]

603Country, having read parts of the Thompson-LaGarde tests, I don't understand why you would want to cite them to defend big-bore bullets.

First, the methodology was suspect. The researchers shot livestock, which often showed little or no immediate reaction to either round.

Second, neither 9mm nor .45acp dropped the majority of the steers used as test subjects, using body shots. Almost all had to be killed with coup de grace to the head, and many of the coups de grace via handgun didn't do the trick, either. "Killed with hammer" was a depressingly frequent result of those tests.

Third, the only advantages noted for the .45 was that it was somewhat more likely to break heavy bones, and that subjectively the researchers thought the wounds it inflicted might require longer recovery times.

[MrAcheson]

yes really. when momentum = zero penatration will stop.conserving momentum in this case is a bad idea IMHO thats why I use hollow points.

I'm not sure where you're going with this. Momentum must be conserved, it's an immutable law of physics. You don't have the option for it not to be conserved.

I agree with you the more momentum generally means more penetration. I disagree that 9ball has a good grasp of fundamental principles.

[freenokia]

There's something to be said for the look of a .45 cal hole staring you in the eye and earth shattering rumble coming from a 357 Magnum.

[MrAcheson]

Is a 9 mil equal to the 44 Mag? I sincerely doubt that it is. Is the 45 ACP equal to the 41 Mag? I doubt it. Does the 45 ACP outrank the 9 Mil?

Absolutely equal? No, probably not. Is it possible that past a certain cartridge capability, it starts making much less of a difference? Quite possibly. You need to penetrate to and through the target's vital organs and make a good sized wound while doing it. Once you have that level of performance, what you do with the bullet matters much more than the specific bullet you're working with.

[secret_agent_man]

"To scare people, you should carry an automatic. But to kill them, use a revolver."
--George S. Patton

[mavracer]

Momentum must be conserved, it's an immutable law of physics.

Momentum as a whole yes. but in this case I ment the bullet's momentum which only pertains to the momentum of or possessed by the bullet once it's energy is transfered the bullet ceases to have momentum.

I disagree that 9ball has a good grasp of fundamental principles.

I agree I just said his calculations were correct, the fact he is misusing the formula leads to practical application of said calculations.

[603Country]

Hi MLeake,

Actually, my thinking is more along the lines of Julian Hatcher's RSP formula from 1934. But, since there are people that disagree with that formula's accuracy, my previous statement follows a more basic logic - big fast bullet versus small slow bullet. If you want knockdown power, go for the big fast bullet, which has more momentum and cross sectional area.

[Daugherty16]

BULLET MOMENTUM DOES NOT MATTER ON A HUMAN

Why? Don't Newtonian physics apply to the human body? Hmm. Momentum is best analyzed and explained using vectors, IIRC. Something has to act on a body in motion in order to change its vector or in this case, stop it cold. Thus the momentum, or motion, is transferred to the 2nd body. The more the momentum, the more the THUMP, in layman's terms.

A ping pong ball weights 2.7 grams which is about 42 grains, or about that of a .22 lr bullet. 675 mph is 990 fps. A ping pong ball at 675 would sting a lot. It would not knock you down.

Exactly correct, sir, and why i chose this analogy. I'd rather be hit with a baseball than a bullet , but i'd take the ping pong ball over the baseball.

Anyway, i'm probably over my head with all this science stuff so i'm dropping out now, but i'll still shoot the biggest bullets i can control from the largest pistol i can conceal. And if i ever have to do it for real, i have complete confidence they will be able to stop a threat - ballistics aside, because i practice and believe i will hit my target.

[JimPage]

I have heard all of these arguments for years. They all have some validity. The problem with any anaysis is that each actual shooting has so many different variables that no one shooting can be exactly matched to another. Not to mention that different bodies will react differently to similar hits.

The exercise is fun and interesting to consider and read, but I don't think anyone is going to convince someone else to change his mind.

[amazon shooter]

Right On Man!

Finally, Mr. Greg Ellifritz has debunked this stoppin power nonsense.

He seems to be the only one who knows "How Many Angels Can Dance On The Head Of A Pin".

[9-ball]

I read a lot of physical nonsense here

but mechanical energy does not have to be conserved by itself. That bullet kinetic energy could, for instance, be converted to heat instead.

You are clearly not getting my post. If the bullet remains in the body as I assumed, ALL of the kinetic energy is transformed in heat.

The 44 magnum bullet used in 9ball's illustration would heat an 8oz cup of coffee up about 4 degrees F if completely converted to heat. That's not very much, is it?

Yes, that's why the energy dump theory just as much as the knock down theory is utter bull****, as I stated before.

One of the first rules of studying collisions and impacts is that you don't use energy unless the collision is perfectly elastic, you use momentum. Shooting someone with a bullet is not a perfectly elastic collision. So this equation is an inappropriate simplification:

Energy is ALWAYS conserved! Even in inelastic collisions. Just because it transformed in heat doesn't mean the energy left. About my formula

F_resistance * x_penetration = Energy

I simplified things a bit as not to get to specific,
here's the complete calculation if you insist:

then you'll have to solve the differential equation
(you'll need to open the images in new window/tab, don't know what the problem is...)
Further derivation will get you s(t) which will allow you to substitute v(t) by v(s(t)). Sorry I won't provide the further steps because I am studying for my exams and want to do something else in my spare time then entering equations

when momentum = zero penatration will stop.conserving momentum in this case is a bad idea IMHO thats why I use hollow points.

Conserving momentum is a bad idea?? Go explain that to Newton please... this makes no sense at all.

Why? Don't Newtonian physics apply to the human body?

Yes they do, but just as the energy isn't even close to the amounts needed to validate the energy dump theory, just as much the momentum totally isn't in the same category needed to knock a human being down.

[MLeake]

If you check, you can find studies where firearms have been shot into sides of beef, dead game animals, etc.

The sides of beef and the bodies don't move much. Doesn't matter if it's a .22LR or a 12ga slug. So, if objects of human size or smaller don't get moved by 12ga and rifle slugs, it's a safe conclusion that humans won't get knocked down by the momentum of any slug from a man-portable centerfire weapon.

RPG's and other rocket propelled items, which don't transfer equivalent momentum directly to the shooter, are a whole 'nother argument...

Seems to me that whether one reads Ellifritz, Fackler, or Marshall and Sanow, the .44 Magnum doesn't do as much better on humans as Hatcher et al would suggest. OTOH, the .44 Magnum is much better suited to large quadrupeds than is the 9mm, .45acp, etc - but that's due to momentum, penetration, and in many cases bullet construction.

In bear country, I like a .44 Magnum. In more settled areas, something between a .38special and a .45acp seems a more practical choice. I have handguns in .38, .357, 9mm, .40s&w, 10mm, .44 magnum, and .45acp. Around town, I mostly carry a caliber starting in .3 (or 9) because I can put those on target the fastest, and they should work well.

[MrAcheson]

You are clearly not getting my post. If the bullet remains in the body as I assumed, ALL of the kinetic energy is transformed in heat.

Except that it isn't because some of the kinetic energy is expended doing plastic deformation to soft tissue or crack propagation in bones, etc. It doesn't all become heat if it does permanent physical damage to body structures. Some of the bullet's energy does (mostly by way of fluid motion), but not all of it.

Energy is ALWAYS conserved! Even in inelastic collisions. Just because it transformed in heat doesn't mean the energy left.

Yes it is always conserved, but it is also transformed into all sorts of different forms. So to solve the energy balance you have to account for as many of the transformations as possible and then solve them all simultaneously. You end up with dynamics and thermodynamics going on at the same time. Not easy. For a problem of this type it generally involves complex computer simulation to do all the work. Most computer simulations don't do this though because it's too much work and takes forever. Unfortunately I can't see your equation to tell if you're accounting for that.

In comparison basing an analysis on momentum conservation lets you drop all the thermodynamics out of the problem and just worry about dynamic motion instead. Much easier, but still hard.

[Boberama]

What it shows is that stopping power is not measurable by "morgue monster" studies.

[mrbro]

Oh my, where to begin.

they that lack evidence and consideration of what the bullets did inside of the targets

EXACTLY! Rather than rely on statistical tabulations of events that have multiple outcomes, I humbly suggest that the gruesome reports from the autopsy tables probably contain the most useful data.

humans won't get knocked down by the momentum of any slug from a man-portable centerfire weapon

EXACTLY! If the momentum of the projectile was enough to knock a 200 lb target down, it will knock the shooter down first.

I think there is information in the data, but it is going to take people who are skilled scientists to make sense of it.

Maybe. Sometimes data is just data, a collection of facts that may or not be related. Problems occur when someone starts looking for causal relationships between the facts. This only works when the data contains ALL the facts, which none of the statistical based shooting data has, IMHO.

energy dump theory

IMHO this is more of a misinformed opinion than a theory. Before anyone gets their knickers in a knot, I used to subscribe in this theory until I really stopped to think about it.

I'll be the first to admit that I do not know what it is that makes a bullet work, or an arrow work, on flesh. I think many people are just as unknowing but are not as comfortable in their ignorance as I am. I think they are trying to understand the process using information passed on by the gun press and what seems like rational explanations using conclusions from these statistical "studies".

What I do know is that business is driven by sales. Sales is driven by product differentiation. Product differentiation is the job of Marketing. Marketing is all about creating a favorable perception. Perception is created by propaganda and hype.

[GoOfY-FoOt]

BOTTOM LINE

Any weapon used to thwart an attack, has to overcome one of two things.
Desire and ability.

Someone MUST have an ongoing mental capacity to cause harm to another human being and they MUST have the physical ability to carry it out.

It does not matter what the statistics say, the odds are irrelevent. The only thing that will relate to any one given situation are the dynamics of that very situation.

Stop their desire to continue attacking you, OR, remove their physical ability.