Handgun stopping power

[Brian Pfleuger]

damage caused by bullet rpm?

Bullets do a whole lot of RPM (minute) but they do all their damage in a tiny fraction of an S (second)

A bullet that penetrates, say, 18" into a target will only rotate the same amount that it rotated in 18" of barrel.... maybe twice.

It also has (essentially) zero rotational momentum, which means it stops spinning very easily and quickly with any resistance.

 

[Frank Ettin]

I've Posted This Before and Might as Well Post it Again Here

Let's consider how shooting someone will actually cause him to stop what he's doing.

• The goal is to stop the assailant.
  
  
• There are four ways in which shooting someone stops him:
  
  
  • psychological -- "I'm shot, it hurts, I don't want to get shot any more."
    
    
  • massive blood loss depriving the muscles and brain of oxygen and thus significantly impairing their ability to function
    
    
  • breaking major skeletal support structures
    
    
  • damaging the central nervous system.
  
  Depending on someone just giving up because he's been shot is iffy. Probably most fights are stopped that way, but some aren't; and there are no guarantees.
  
  Breaking major skeletal structures can quickly impair mobility. But if the assailant has a gun, he can still shoot. And it will take a reasonably powerful round to reliably penetrate and break a large bone, like the pelvis.
  
  Hits to the central nervous system are sure and quick, but the CNS presents a small and uncertain target. And sometimes significant penetration will be needed to reach it.
  
  The most common and sure physiological way in which shooting someone stops him is blood loss -- depriving the brain and muscles of oxygen and nutrients, thus impairing the ability of the brain and muscles to function. Blood loss is facilitated by (1) large holes causing tissue damage; (2) getting the holes in the right places to damage major blood vessels or blood bearing organs; and (3) adequate penetration to get those holes into the blood vessels and organs which are fairly deep in the body. The problem is that blood loss takes time. People have continued to fight effectively when gravely, even mortally, wounded. So things that can speed up blood loss, more holes, bigger holes, better placed holes, etc., help.
  
  So as a rule of thumb --
  
  
  • More holes are better than fewer holes.
    
    
  • Larger holes are better than smaller holes.
    
    
  • Holes in the right places are better than holes in the wrong places.
    
    
  • Holes that are deep enough are better than holes that aren't.
    
    
  • There are no magic bullets.
    
    
  • There are no guarantees.
  
  
• With regard to the issue of psychological stops see
  
  
  • this study by Greg Ellifritz. And take special notice of his data on failure to incapacitate rates:
    
    
    
    ​
    
    
    As Ellifritz notes in his discussion of his "failure to incapacitate" data (emphasis added):

    ...Take a look at two numbers: the percentage of people who did not stop (no matter how many rounds were fired into them) and the one-shot-stop percentage. The lower caliber rounds (.22, .25, .32) had a failure rate that was roughly double that of the higher caliber rounds. The one-shot-stop percentage (where I considered all hits, anywhere on the body) trended generally higher as the round gets more powerful. This tells us a couple of things...
    
    In a certain (fairly high) percentage of shootings, people stop their aggressive actions after being hit with one round regardless of caliber or shot placement. These people are likely NOT physically incapacitated by the bullet. They just don't want to be shot anymore and give up! Call it a psychological stop if you will. Any bullet or caliber combination will likely yield similar results in those cases. And fortunately for us, there are a lot of these "psychological stops" occurring. The problem we have is when we don't get a psychological stop. If our attacker fights through the pain and continues to victimize us, we might want a round that causes the most damage possible. In essence, we are relying on a "physical stop" rather than a "psychological" one. In order to physically force someone to stop their violent actions we need to either hit him in the Central Nervous System (brain or upper spine) or cause enough bleeding that he becomes unconscious. The more powerful rounds look to be better at doing this....

    
    
    1. There are two sets of data in the Ellifritz study: incapacitation and failure to incapacitate. They present some contradictions.
       
       
       • Considering the physiology of wounding, the data showing high incapacitation rates for light cartridges seems anomalous.
         
         
       • Furthermore, those same light cartridges which show high rates of incapacitation also show high rates of failures to incapacitate. In addition, heavier cartridges which show incapacitation rates comparable to the lighter cartridges nonetheless show lower failure to incapacitate rates.
         
         
       • And note that the failure to incapacitate rates of the 9mm Luger, .40 S&W, .45 ACP, and .44 Magnum were comparable to each other.
         
         
       • If the point of the exercise is to help choose cartridges best suited to self defense application, it would be helpful to resolve those contradictions.
         
         
       • A way to try to resolve those contradictions is to better understand the mechanism(s) by which someone who has been shot is caused to stop what he is doing.
       
       
    2. The two data sets and the apparent contradiction between them (and as Ellifritz wrote) thus strongly suggest that there are two mechanisms by which someone who has been shot will be caused to stop what he is doing.
       
       
       • One mechanism is psychological. This was alluded to by both Ellifritz and FBI agent and firearms instructor Urey Patrick. Sometimes the mere fact of being shot will cause someone to stop. When this is the stopping mechanism, the cartridge used really doesn't matter. One stops because his mind tells him to because he's been shot, not because of the amount of damage the wound has done to his body.
         
         
       • The other mechanism is physiological. If the body suffers sufficient damage, the person will be forced to stop what he is doing because he will be physiologically incapable of continuing. Heavier cartridges with large bullets making bigger holes are more likely to cause more damage to the body than lighter cartridges. Therefore, if the stopping mechanism is physiological, lighter cartridges are more likely to fail to incapacitate.
       
       
    3. And in looking at any population of persons who were shot and therefore stopped what they were doing, we could expect that some stopped for psychological reasons. We could also expect others would not be stopped psychologically and would not stop until they were forced to because their bodies became physiologically incapable of continuing.
       
       
    4. From that perspective, the failure to incapacitate data is probably more important. That essentially tells us that when Plan A (a psychological stop) fails, we must rely on Plan B (a physiological stop) to save our bacon; and a heavier cartridge would have a lower [Plan B] failure rate.
  
  
• Also see the FBI paper entitled "Handgun Wounding Factors and Effectiveness", by Urey W. Patrick. Agent Patrick, for example, notes on page 8:

  ...Psychological factors are probably the most important relative to achieving rapid incapacitation from a gunshot wound to the torso. Awareness of the injury..., fear of injury, fear of death, blood or pain; intimidation by the weapon or the act of being shot; or the simple desire to quit can all lead to rapid incapacitation even from minor wounds. However, psychological factors are also the primary cause of incapacitation failures.
  
  The individual may be unaware of the wound and thus have no stimuli to force a reaction. Strong will, survival instinct, or sheer emotion such as rage or hate can keep a grievously wounded individual fighting....

• And for some more insight into wound physiology and "stopping power":
  
  
  • Dr. V. J. M. DiMaio (DiMaio, V. J. M., M. D., Gunshot Wounds, Elsevier Science Publishing Company, 1987, pg. 42, as quoted in In Defense of Self and Others..., Patrick, Urey W. and Hall, John C., Carolina Academic Press, 2010, pg. 83):

    In the case of low velocity missles, e. g., pistol bullets, the bullet produces a direct path of destruction with very little lateral extension within the surrounding tissue. Only a small temporary cavity is produced. To cause significant injuries to a structure, a pistol bullet must strike that structure directly. The amount of kinetic energy lost in the tissue by a pistol bullet is insufficient to cause the remote injuries produced by a high-velocity rifle bullet.

    
    
  • And further in In Defense of Self and Others... (pp. 83-84, emphasis in original):

    The tissue disruption caused by a handgun bullet is limited to two mechanisms. The first or crush mechanism is the hole that the bullet makes passing through the tissue. The second or stretch mechanism is the temporary wound cavity formed by the tissue being driven outward in a radial direction away from the path of the bullet. Of the two, the crush mechanism is the only handgun wounding mechanism that damages tissue. To cause significant injuries to a structure within the body using a handgun, the bullet must penetrate the structure.

    
    
  • And further in In Defense of Self and Others... (pp. 95-96, emphasis in original):

    Kinetic energy does not wound. Temporary cavity does not wound. The much-discussed "shock" of bullet impact is a fable....The critical element in wounding effectiveness is penetration. The bullet must pass through the large blood-bearing organs and be of sufficient diameter to promote rapid bleeding....Given durable and reliable penetration, the only way to increase bullet effectiveness is to increase the severity of the wound by increasing the size of the hole made by the bullet....

  
  
• And sometimes a .357 Magnum doesn't work all that well. LAPD Officer Stacy Lim who was shot in the chest with a .357 Magnum and still ran down her attacker, returned fire, killed him, survived, and ultimately was able to return to duty. She was off duty and heading home after a softball game and a brief stop at the station to check her work assignment. According to the article I linked to:

  ... The bullet ravaged her upper body when it nicked the lower portion of her heart, damaged her liver, destroyed her spleen, and exited through the center of her back, still with enough energy to penetrate her vehicle door, where it was later found....

 

[44 AMP]

Any gun that can kill a bear can stop an attacking bear. The problem is that people have to make a good shot in a very short period of time, on a difficult to hit target, which is moving very fast in order to stop an attacking bear.

Most people have a rather difficult time with that. I would.

Bear have been killed with 9mm Luger rounds. Parts of people and a shot dry .38 snubnose have been found, also.

The best bear defense is to properly use what is under you hat. Eyes, ears, even nose, but especially BRAIN, and feet!

Heavy handguns have the power of light rifles, measure it any way you want, done right, they all make the critter dead. DRT is nice, but that's up to YOU more than anything else.

 

[Guv]

Hunter Customs,

Going back to the 270/130 or 45-70/300 creates a major conflict in my brain. First response would be the 45-70, I have shot really big feral hogs with a 444Marlin loaded with 265gr Hornadys with good results. I also have a 270 that has taken a number of hogs and deer, also with good results. Neither one produced vastly different results than the other so given equal as possible bullet construction I still don't have a clear choice made up in my mind.
Brian,

We are talking about T/C Encores, aren't we?

 

[Theohazard]

Yep, I'll admit, I'm old school, when it comes to packing a handgun I don't buy into all the hype about light bullets and high velocity.
So in most cases when packing a handgun for self defense any caliber that starts with a 4 and ends with a 4 or 5 is my first choice.

But you do buy into the hype of the Taylor KO Factor and the hype that there's a significant difference between common self-defense calibers? Taylor's formula has absolutely no scientific basis and has proven to be significantly flawed. And when it comes to shootings of two-legged predators, numerous studies have shown there's very little difference between the results produced by the common self-defense calibers. So at some point "old school" crosses over into "willfully ignoring new information and sticking with disproven concepts".

True it's not a physics formula, it's one man's opinion with a lot of real world experience.
That packs more weight then a physics formula with me.

You're making the classic logical mistake of expecting personal experience to be an accurate and objective measurement of something as detailed and complicated as this. Using an individual person's unscientific anecdotal evidence to measure different calibers' effectiveness is a logical fallacy and has no actual scientific usefulness.

As the psychologist Daniel Schacter once said, "The self is hardly a neutral observer of the world." It's well-established that even the most highly-trained expert brings personal biases to any attempt to evaluate data. And, in this case, examining the subtle differences between different calibers requires examining a huge amount of data in a scientifically objective way, something that Taylor didn't do. Personal experience can be a useful tool, but it can also very easily lead to incorrect conclusions.

even with training a full auto 223 is not that easy to keep on target.
I seriously doubt you will get 30 hits with a full auto 223.

This is simply untrue. Have you ever fired a full-auto .223? It's remarkably easy to control with a little bit of training. Using a good technique it would be fairly easy to get 30 full-auto hits on a target as large as a charging bear. Sure, it would also be easy to panic and miss some of those shots because you have a bear charging at you, but that's true with any firearm.

 

[Tomac]

Well said, Frank! [/thread]
Tomac

 

[Harvey]

Physics are a funny thing. But in the end, Bob says it quite eloquently:

Yep, I'll admit, I'm old school, when it comes to packing a handgun I don't buy into all the hype about light bullets and high velocity.
So in most cases when packing a handgun for self defense any caliber that starts with a 4 and ends with a 4 or 5 is my first choice.

Best Regards
Bob Hunter

 

[JD0x0]

For those that are so confident in the TKO factor. 1 example.
You're about to get attacked by a bear...

You've got two weapons, that you can readily shoulder and fire at the SAME exact speed. For this example, we're going to assume these rifles have weight and add-ons so that they recoil about the same too.
One is a semiauto 45ACP rifle, with a TKO factor of 13. Pushing a 230 grain load at about 900fps.
The other is a semiauto .260 Remington pushing a 120 grain bullet @ 2800fps. It has a TKO factor of 12.

Which one is better for bear defense? They both are loaded with the same amount of rounds in the mag, and recoil similarly. For this example, lets assume that these rifles shoot equally well, the only difference being the load, and the TKO factor.
Soo, who's going with the .45acp because it has the higher TKO?

 

[Guv]

I wouldn't touch that 45 with a 10 foot pole!

 

[manta49]

And note that the failure to incapacitate rates of the 9mm Luger, .40 S&W, .45 ACP, and .44 Magnum were comparable to each other.

That type of comparison only makes sense to me . If the person was hit in exactly the same place , were wearing the same clothing , the same bullet type was used etc. I think there are too many variables to rely on that type of comparisons.

 

[Theohazard]

If the person was hit in exactly the same place , were wearing the same clothing , the same bullet type was used etc. I think there are too many variables to rely on that type of comparisons.

That's why studies like this need a large sample size of data. The way you minimize the effects of those different variables is to examine a very large number of shootings, that way those variables are mostly blurred out.

 

[Harvey]

For those that are so confident in the TKO factor. 1 example.
You're about to get attacked by a bear...

You've got two weapons, that you can readily shoulder and fire at the SAME exact speed. For this example, we're going to assume these rifles have weight and add-ons so that they recoil about the same too.
One is a semiauto 45ACP rifle, with a TKO factor of 13. Pushing a 230 grain load at about 900fps.
The other is a semiauto .260 Remington pushing a 120 grain bullet @ 2800fps. It has a TKO factor of 12.

Which one is better for bear defense? They both are loaded with the same amount of rounds in the mag, and recoil similarly. For this example, lets assume that these rifles shoot equally well, the only difference being the load, and the TKO factor.
Soo, who's going with the .45acp because it has the higher TKO?

A challenging comparison, indeed. But in the spirit of the OP (handgun stopping power) I doth protest. I must have left my .260 pistol in my other pants, so the .45 it is.

 

[manta49]

That's why studies like this need a large sample size of data. The way you minimize the effects of those different variables is to examine a very large number of shootings, that way those variables are mostly blurred out

You might see from 50 to 400 a large sample of data I don't. And certainly not enough to blur out the many variables. But that's just my opinion.

Some variables I can think of, I am sure there are more.
1 ammo type.
2 firearm type , length of barrel.
3 distance of shot.
4 type of clothing , layers.
5 angle of shot.
6 where the bullet hit.
7 the person that is shot, what will stop someone will not stop another.
8 the build of the person.

 

[Theohazard]

You might see from 50 to 400 a large sample of data I don't. And certainly not enough to blur out the many variables. But that's just my opinion.

I don't know enough about the statistics involved to say how large a sample size is needed. But my point is simply that those variables can be negated by a large enough sample size and proper statistical analysis.

 

[Nanuk]

I have. He took his own life. We smelled him from outside his home. I can go into detail if the mods want me to.

You certainly do not need a degree in physics to figure that out.

 

[DannyB1954]

I think if the rounds were blowing through these, a deer a hog or human wouldn't stand a chance if shots were well placed.

A well placed 22lr will kill most anything. Police forces don't agree on what is the best SD round to use. Some use 9mm, others 40S&W, others 45 ACP, 357Sig and on and on. So basically put it where it counts and it will count.
Shot placement trumps caliber.

 

[44 AMP]

all else being equal, bigger holes are better. Unfortunately, all else is never, ever, equal.

Ok, Brian, I grant after the fact permission to use my sig line!
or a variation, of the same,

 

[Brian Pfleuger]

I knew I'd seen that somewhere, couldn't quite recall where.

 

[Guv]

I think that expecting your 2nd, 3rd or 4th shot to have better placement than your first is totally unrealistic.

 

[DannyB1954]

I think that expecting your 2nd, 3rd or 4th shot to have better placement than your first is totally unrealistic.

Very good point. My thinking is that my objective is to stop the aggression. The more shots that I am able to place, the greater the chance that I will hit a bone or something that will hurt like hell. A lot of soft tissue shots go unnoticed by the victim. Also if there is more than one assailant, firing something that requires a lot of time to get back on target is not beneficial.