Stopping power – more support for what we already knew

Well… what some of us already knew. A simple Google search shows that much myth and misinformation are still being passed about.

There’s a post over at that discusses “stopping power” (h/t Packing Rat). This is a topic that gets beat to death, but at least here we’ve got someone actually working with data and not personal bias. He collected some 10 years of data and looked at the following:

  • Number of people shot
  • Number of rounds that hit
  • On average, how many rounds did it take for the person to stop his violent action or be incapacitated? For this number, I included hits anywhere on the body.
  • What percentage of shooting incidents resulted in fatalities. For this, I included only hits to the head or torso
  • What percentage of people were not incapacitated no matter how many rounds hit them
  • Accuracy. What percentage of hits was in the head or torso. I tracked this to check if variations could affect stopping power. For example, if one caliber had a huge percentage of shootings resulting in arm hits, we may expect that the stopping power of that round wouldn’t look as good as a caliber where the majority of rounds hit the head.
  • One shot stop percentage- number of incapacitations divided by the number of hits the person took. Like Marshall’s number, I only included hits to the torso or head in this number.
  • Percentage of people who were immediately stopped with one hit to the head or torso

I think that’s a pretty good set of things to look at, given the goals and the typical arguments that surround this issue.

Then he looked at the common carried pistol rounds:

  • .25 ACP
  • .22 (short, long, and long rifle)
  • .32 (long and ACP)
  • .380 ACP
  • .38 Special
  • 9mm Luger
  • .357 (mag and SIG)
  • .40 S&W
  • .45 ACP
  • .44 Mag
  • Rifle (all centerfire)
  • shotgun (all, but 90% were 12 gauge)

But he also doesn’t think he has enough data to back up .25, .32, and .44 well enough. He also noted that over half the 9mm shootings were with ball ammo, and that likely skews those numbers.

Before getting into his numbers, my quick conclusion from the number is what has long been said: all pistol rounds suck. It doesn’t matter the caliber, that it begins with a 4 or doesn’t… they all suck. Now, let’s start talking rifles and shotguns… but, you can’t carry a rifle around (in many places), thus why we carry handguns.  As well, “one shot stop” is possible, but you shouldn’t bet your farm on it. You must work to stop the threat, and if that means more than one shot, it does.

Side note: shotgun seems pretty darn effective at getting things to stop. Tom Givens touched on this in his Defensive Shotgun class. That we consider the low ammo capacity of a shotgun to be a negative, and in a way it is, and the likelihood of needing a second shot is small(er), but still possible (click-chunk-chunk is the sound of 1 shot from a pump shotgun). This data appears to back that up. So, more ammo capacity is good, a side-saddle or buttcuff or some other means of having more shells on the shotgun is good, a habit of “shoot one load one; shoot two load two” is good, but we shouldn’t get too caught up in the shotgun capacity argument.

Now, onto the study author’s conclusions.

One thing that stood out to me was his take on number of rounds and rate of fire:

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. Something else to look at here is the question of how fast can the rounds be fired out of each gun. The .38spl probably has the slowest rate of fire (long double action revolver trigger pulls and stout recoil in small revolvers) and the fewest rounds fired to get an incapacitation (1.87). Conversely the 9mm can probably be fired fastest of the common calibers and it had the most rounds fired to get an incapacitation (2.45). The .40 (2.36) and the .45 (2.08) split the difference. It is my personal belief that there really isn’t much difference between each of these calibers. It is only the fact that some guns can be fired faster than others that causes the perceived difference in stopping power. If a person takes an average of 5 seconds to stop after being hit, the defender who shoots a lighter recoiling gun can get more hits in that time period. It could be that fewer rounds would have stopped the attacker (given enough time) but the ability to fire more quickly resulted in more hits being put onto the attacker. It may not have anything to do with the stopping power of the round.

That seems some worthy food for thought. You’d need further study into this particular aspect to really know for sure, but certainly he raises a topic worth addressing and considering.

And in the end, his conclusion reinforces what others have put forth:


Now compare the numbers of the handgun calibers with the numbers generated by the rifles and shotguns. For me there really isn’t a stopping power debate. All handguns suck! If you want to stop someone, use a rifle or shotgun!

What matters even more than caliber is shot placement. Across all calibers, if you break down the incapacitations based on where the bullet hit you will see some useful information.

Head shots = 75% immediate incapacitation
Torso shots = 41% immediate incapacitation
Extremity shots (arms and legs) = 14% immediate incapacitation.

No matter which caliber you use, you have to hit something important in order to stop someone!



So there you go. The “power” only matters so much, but handgun rounds just won’t have it period (move to a long gun for power). Being able to put the shot where it needs to go is what matters, and that’s a matter of both accuracy and penetration.

Don’t get caught up in caliber wars. What matters is that you can have a gun that addresses your needs. By that I mean things like, maybe you are a tiny woman that doesn’t have the body size and shape to conceal a 1911 Government model, or maybe you’re a big man who has to carry in a NPE (non-permissive environment), or maybe you’ve got arthritic hands… so, you need to work within your limitations. But within that, use what enables you to hit what you need to hit. I’d argue you’d want to also ensure it enables you to hit what you need to hit rapidly and repeatedly (e.g. follow-up shots are important to get off quickly and accurately). And then you have further choices as you narrow down your selection, capacity is good because 1. follow-up shots are likely, 2. predators tend to travel in packs. When it comes to ammo, pick quality ammo designed for the task (e.g. expanding ammo, like Speer Gold Dot; not ball like the Winchester white box you use for practice).

Even if all you can have is a .22, it’s better than nothing. Just put it where it matters.

The conclusions of the study are nothing new, but it’s just more data that hopefully will put an end to the endless debate. But, I doubt it, given the 4 pages of debate that occurs after the posting…. 🙂


6 thoughts on “Stopping power – more support for what we already knew

  1. Same argument put forward by the IWBA International Wound Ballistics Association. Coroners studying real gunshot wounds from real guns in real gunfights on real people. They determined that handguns suck and if it is above 9mm+P it really doesn’t matter what you shoot but how well you shoot it.

    • Yup. Like I said, stuff we already knew, but it’s still useful to build up the mountain of data.

      But unfortunately, it doesn’t seem to put an end to the debate. *sigh*

      I do think the one angle he mentioned would be worth looking into. That is, because something like a 9 can be fired faster than a 40 thus data could be that 9 “requires more hits” merely because one can and does get more shots off in the time it takes for the CNS to shut down (or the attacker to otherwise stop), does that potentially skew the data? I’m not sure it really needs investigation because again, they all suck… but still, to me that was a new angle put forth in the debate.

  2. I do think the one angle he mentioned would be worth looking into. That is, because something like a 9 can be fired faster than a 40 thus data could be that 9 “requires more hits” merely because one can and does get more shots off in the time it takes for the CNS to shut down

    This is a new notion to me, too. How could this be investigated further?

    The tendency of people to shoot until the threat has ended — or more precisely, until they perceive that the threat has ended — makes me guess that there are some “extra” shots fired in all calibers. That is, inconsequential shots fired after the threat had actually ended, but before the shooter was convinced that the threat had ended. The faster the shooter, due to some combination of skill, caliber, and gun, the more “extra” shots you’d expect.

    As you say, they all suck. This is probably way down in the noise, but an interesting new nugget to ponder, nonetheless.

    • Right! So how much is data perhaps skewed due to that? Hard to say, and I too am not really sure how you could test this.

      and perhaps, could that also be why shotguns have such a low number of shots? because it’s slower, in theory, to work that pump action and battle the recoil to get 3 shots off vs. the time it takes to get 3 shots off from a semi-auto handgun in 9mm?

      It would be interesting to see if this could be somehow looked at. Not sure how much it would matter, but sometimes academics for the pure sake of knowledge can be fun too. 🙂

  3. Great article. It’s awesome to see actual data with the breakdown of types of guns, ammos, etc. Someone should start collecting all of this and future data to truly be able to come to strong conclusions regarding stopping power, etc.

    • The thing is, the data is all out there…. trouble is, people don’t want to pay attention to it, no matter how collected and in their face it is.

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