Trainer: For Self-Defense, Carry What You Want

Rounds to Incapacitation

Greg Ellifritz, a full-time firearms and defensive tactics training officer for a central Ohio police department and the president of Active Response Training, recently conducted an extensive self-study of cartridge and shotshell stops. He graciously allowed the CTD Chronicles to excerpt some of his findings—which challenge conventional wisdom about which cartridges are best for self defense.

Rounds to Incapacitation
Rounds to Incapacitation

Conclusion: Ellifritz writes, “The results I got from the study lead me to believe that there really isn’t that much difference between most defensive handgun rounds and calibers. None is a death ray, but most work adequately…even the lowly .22s. I’ve stopped worrying about trying to find the ‘ultimate’ bullet. There isn’t one. And I’ve stopped feeling the need to strap on my .45 every time I leave the house out of fear that my 9mm doesn’t have enough ‘stopping power.’ Folks, carry what you want. Caliber really isn’t all that important.”

Earlier in the piece he writes, “I’ve been interested in firearm stopping power for a very long time. I remember reading Handguns magazine back in the late 1980s when Evan Marshall was writing articles about his stopping power studies. When Marshall’s first book came out in 1992, I ordered it immediately, despite the fact that I was a college student and really couldn’t afford its $39 price tag. Over the years I bought all of the rest of Marshall’s books as well as anything else I could find on the subject. I even have a first edition of Gunshot Injuries by Louis Lagarde published in 1915.

“Every source I read has different recommendations. Some say Marshall’s data is genius. Some say it is statistically impossible. Some like big heavy bullets. Some like lighter, faster bullets. There isn’t any consensus. The more I read, the more confused I get.” Ellifritz continues, “One thing I remember reading that made a lot of sense to me was an article by Massad Ayoob. He came out with his own stopping power data around the time Marshall published Handgun Stopping Power. In the article, Ayoob took his critics to task. He suggested that if people didn’t believe his data, they should collect their own and do their own analysis. That made sense to me. So that’s just what I did. I always had a slight problem with the methodology of Marshall and Sanow’s work. For consistency purposes, they ONLY included hits to the torso and ONLY included cases where the person was hit with just a single round. Multiple hits screwed up their data, so they excluded them. This lead to an unrealistically high stopping power percentage, because it factored out many of the cases where a person didn’t stop! I wanted to look at hits anywhere on the body and get a realistic idea of actual stopping power, no matter how many hits it took to get it. So I started collecting data.” “Over a 10-year period,” Ellifritz said, “I kept track of stopping power results from every shooting I could find. I talked to the participants of gunfights, read police reports, attended autopsies, and scoured the newspapers, magazines, and Internet for any reliable accounts of what happened to the human body when it was shot. I documented all of the data I could; tracking caliber, type of bullet (if known), where the bullet hit and whether or not the person was incapacitated. I also tracked fatalities, noting which bullets were more likely to kill and which were not. It was an exhaustive project, but I’m glad I did it and I’m happy to report the results of my study here. … I don’t have any dog in this fight! I don’t sell ammo. I’m not being paid by any firearm or ammunition manufacturer. I carry a lot of different pistols for self defense. Within the last 2 weeks, I’ve carried a .22 magnum, a .380 auto, a .38 spl revolver, 3 different 9mm autos and a .45 auto. I don’t have an axe to grind. If you are happy with your 9mm, I’m happy for you. If you think that everyone should be carrying a .45 (because they don’t make a .46), I’m cool with that too. I’m just reporting the data. If you don’t like it, take Mr. Ayoob’s advice…do a study of your own.

Selected Highlights

.22 (short, long and long rifle)

  • # of people shot – 154
  • # of hits – 213
  • % of hits that were fatal – 34%
  • Average number of rounds until incapacitation – 1.38
  • % of people who were not incapacitated – 31%
  • One-shot-stop % – 31%
  • Accuracy (head and torso hits) – 76%
  • % actually incapacitated by one shot (torso or head hit) – 60%

9mm Luger

  • # of people shot – 456
  • # of hits – 1121
  • % of hits that were fatal – 24%
  • Average number of rounds until incapacitation – 2.45
  • % of people who were not incapacitated – 13%
  • One-shot-stop % – 34%
  • Accuracy (head and torso hits) – 74%
  • % actually incapacitated by one shot (torso or head hit) – 47%

Shotgun (All, but 90% of results were 12 gauge)

  • # of people shot – 146
  • # of hits – 178
  • % of hits that were fatal – 65%
  • Average number of rounds until incapacitation – 1.22
  • % of people who were not incapacitated – 12%
  • One-shot-stop % – 58%
  • Accuracy (head and torso hits) – 84%
  • % actually incapacitated by one shot (torso or head hit) – 86%

Ellifritz writes, “I think the most interesting statistic is the percentage of people who stopped with one shot to the torso or head. There wasn’t much variation between calibers. Between the most common defensive calibers (.38, 9mm, .40, and .45) there was a spread of only eight percentage points. No matter what gun you are shooting, you can only expect a little more than half of the people you shoot to be immediately incapacitated by your first hit.” He concluded, “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.” Greg Ellifritz is the full time firearms and defensive tactics training officer for a central Ohio police department and the president of Active Response Training. He holds instructor or master instructor certifications in more than 75 different weapon systems, defensive tactics programs and police specialty areas. Greg has a master’s degree in Public Policy and Management and has been an instructor for both the Ohio Peace Officer’s Training Academy and the Tactical Defense Institute. He can be reached through his website at The full version of the study is available on the Buckeye Firearms website.

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Comments (24)

  1. And the battle continues to rage! It’s great reading everyones views on this ongoing topic. Especially when the comments are from intelligent people like those above who know what they are talking about. I am a Police officer in Arizona with 32 years. My department started me with a Model 15 S&W and 12 round of .38 special. since then we have transitioned to Sig 9mm’s and .45’s, and finally to the .40 SW Sig. I’ve listened to hundreds of arguments on the range about which round we should be carrying and why. While i always felt the calibers we have used over the years were were probably adequate for the time, I have always believed that it is not what you shoot. It’s how well you shoot it! Choose a weapon that you are comfortable with and keep shooting until the bad guy is no longer in a vertical position. When we went to the sig 226 9mm or the 220 .45 acp i eagerly chose the 226 9mm with a total of 46 rounds carried on my person. About 90% chose the .45 . When qualifying i was always kidded by the range instructors about the 9mm. “why do you carry that wood pecker gun when you shoot expert? I just told them I was confident in the performance of the round, I shot it well, and if I ever get in a shootout I may be glad I have 46 chances to hit the bad guy. Keep writing the comments guys. It’s great to hear everyones opinions.

  2. It is obvious to every hunter that shot placement is what will kill the game, and kill the game immediately. It is also obvious that a 12 gauge 3″ Magnum slug center mass will stop any attacker within 30 seconds or so as they massively bleed out, lose blood pressure and pass out cold. The real question is: what round will incapacitate (not stop psychologically) the aggressor-attacker quickly when you are unable to get good bullet placement? I have read quite a lot on this and I still think Sanow and Marshall make more sense than their critics. Their recommendation of the .357 Magnum and .45 ACP are rooted in ballistic studies as well as case studies and I carry a .357 snub airweight.

  3. I’ve known this for years. I have listened to these arguments for the past 50 years, and the reality is exactly what some of the posters are saying–“no one wants to get shot a little.” And the advice is completely correct. Use whatever works for you. I certainly would not feel undergunned with a 22lr. I’ve always wondered what this morbid fascination is with large bores in self defense situations.(I own three 45s) Sure it may be applicable in a war time environment, but you going to a restaurant and getting mugged? Or having to deal with a home intruder? Therefore to see some of the logical and common sense comments posted here makes my heart glad. Now if you really want to see something just as interesting, start studying the ballistic tables of the various popular rifles–such as the 308, 30-06, 44 mag rifle, 444 Marlin, 45-70, 7mm mag, 375 H&H and my favorite, the 35 Whelan. You will find similar results–that many of the are essentially very similar in power and knockdown ability. As you increase bore size and decrease velocity, it’s really pretty much the same. Most of these discussions are by gun writers that need something to talk about–kind of like Monks discussing how many angels can fit on the head of a pin.

  4. I precisely needed to say thanks once more. I’m not certain the things that I would have undertaken without the entire solutions revealed by you concerning such a situation. It was a scary setting for me personally, however , discovering your skilled technique you handled the issue took me to jump with gladness. Extremely happy for your guidance and as well , pray you know what a powerful job you have been undertaking training some other people by way of your website. Most probably you have never met all of us.

  5. No one wants to be shot, even a little. I wear very light shorts & tee shirt as my daily uniform. I carry a Kel-tec 32 with a Crimson Trace laser & 10 rd mag (10.5 oz loaded) or a S&W 317 22LR (11 oz loaded). For heavier clothing I carry a Diamondback DB 9 9mm (16 oz loaded). Because of my preference for light weight and light weight clothing, I would rather “carry small & carry cold”. I practice weekly and have carried a 22 daily for over 30 years. I always have a gun, it may be small caliber, but I always have a gun. I killed a bird feeder robbing squirrel yesterday with a Winchester model 11 CO2 BB gun yesterday as it ran thru the tree limbs. Practice helps. Any practice, BB gun, pellet gun, aiirsoft gun, 22LR pistol or revolver will improve your accuracy.

  6. A few years ago, when talking to a very experienced Russian military man, I asked him (through an interpreter) about caliber recommendations. He said before discussing what round is best I would need to hit my foot with a hammer as hard as I can, and only then he would discuss it. After scratching my head about this, I realized the meaning of it. They ALL hurt a lot, and such bickering about calibers is largely irrelevant.

  7. I am a Master Texas Peace Officer, but was a paramedic for 16 years before I became a cop. I can truly testify that in 34 years of public safety I’ve seen many more dead bodies with .22 holes in them than any other pistol round.

    I have to agree – shot placement, and keep shooting ’til the gun goes “click” instead of “bang” is the way to stop a bad guy (which is why my off-duty weapon is the Beretta .380 and 14 HydraShok cartridges). Regardless of everything, though, is the famous KLEIN’S 1st LAW OF SURVIVAL:

    “The second to last thing a morally responsible, prudent person wants to do is kill another human being, regardless how reprehensible, villainous or dangerous that person might be.

    “The last thing this morally responsible, prudent person wants to do is be killed by that reprehensible, villainous and dangerous person.”

  8. Yes, definitely a controversial debate of a subject here, and no clear cut answers other than the fact mentioned above about virtually any caliber is better than throwing rocks (unless you do like Wile E. Coyote and purchase Acme Rocks which increase in weight after thrown). This even comes back to the debate among alligator hunters in the swamps….22LR, a .22 WMR, or even a .17 HMR to the only realistic sensitive spot on the back of an alligator’s head (about the size of a quarter) before dragging a 800 to 950 pound ‘gator into the boat with you! If you watched the new episode a few days back, you got to see a stun shot that was not an incapacitation, and only seconds after the gator was dropped over into the boat the huge ancient beast decided that it was done taking a short nap! Regardless with the gators, exact placement is more important than caliber, and the window for error is not large at all even at virtually point blank range.

    One source I often go back to is the ballistic charts where the Taylor KnockDown Index appears, and among the most popular medium-sized handgun calibers ( .38, 9mm Luger, .40 S&W, .45 ACP ), there are some ups and downs among the calibers but overall the total energy available comes up to somewhat of a wash and you have to begin looking into additional factors to sort things out. One thing I have not seen thus far is what type of ammunition was in use on the cases studied, however I’m sure that most anyone here is well aware of which ones are the more effective stoppers and which ones tend to zing through and continue on (but a lot of people who carry guns and haven’t studied the effects think a bullet is a bullet, however this is not necesarily the case!). Practically anyone here reading this will immediately gravitate towards hollow points for expansion and energy transfer, but just how many of those toting firearms actually go to the extra expense to buy defensive-grade premium ammunition instead of the much cheaper FMJ rounds that lack energy transfer capability and often tend to penetrate right out the back side and continue on, losing part of their total energy to overpenetration? I’d be willing to bet that many of the ballistically uneducated ones out there think the FMJ is a better defensive round, due to the fact that it has better penetration capabilities, yet these same people forget that energy transfer to the intended target is where your stopping power originates. Velocity often tracks along with available energy, but if the bullet lacks the capability to rapidly expand which greatly increases the frontal surface area of the bullet and makes a tremendous difference in how much energy is either transferred to the target or lost to the bullet wandering on down the road at a reduced speed (after zinging right through the inside of the target but didn’t hit anything hard enough to stop it). Of course, a larger caliber presents more frontal surface area to a bullet which tend to decelerate even a non-deforming bullet faster, but a high velocity small caliber bullet will want to maintain its momentum better due to less resistance encountered and thus less available energy transferred from the bullet to the target upon impact and penetration (the power is there, but all may not be able to be utilized). From a physical projectile frontal surface area alone, the physics tend to favor the larger caliber for better stopping power (expanding bullet or even non-expanding), and some of the misconceptions may originate from projectile restrictions in place which cause military groups to use FMJ loads instead of more effective hollow points (or at least more effective for energy transfer in a shorter distance, yielding extra potential damage and increasing the severity of the wounds), and the FMJ requirements may convince some that these lesser energy transfer rounds are better for a defensive load (not necessarily the case unless you need to initially penetrate through a barrier). I can’t really speculate on a figure of those who may be carrying and using non-expanding ammunition by choice, but between the ammunition availability and cost factors I’m sure that some never even think past the easiest to find and cheapest ammo they can get their hands on (and never slow down to think that their life may depend on it). Maybe half of those toting handguns around have never even given a second thought to which projectiles are more effective for defensive use, but the knowledgeable ones will instantly reach past the readily available FMJ’s and grab the more expensive hollow points instead and even then they tend to be picky upon which hollow point they want (all hollow points are NOT created equal at all). How much does this choice of ammunition skew the results reported for cases where a choice for a better load could be made, but selecting more effective ammo is not always an option.

    Back to the more common medium-sized handgun calibers, the total energy available factors that come up when putting the velocity and the grains of weight together will push the overall readings one direction, where the frontal surface area may either add or subtract away from the first value. The larger calibers traveling slower have a tendency to produce a higher transfer of energy, especially when hollow points may give a expansion factor of 150% of original diameter to even 200% of original diameter in some of the newest defensive bullets which have polymer-filled hollow points riding out front of them. These polymer-filled hollow points are a huge new improvement towards swapping potential energy into kinetic energy, since the polymer tends to prevent either fabric clogging of the hollow point cavity or collapse of the hollow nose back in upon itself which robs any further expansion capabilities. If you want to see some good examples of these new polymer-filled hollow point projectiles, the first two that come to mind are the new Hornady FTX bullet with the front hollow point filled up flush with red polymer (the Zombie from Hornady looks somewhat similar in configuration except the color is closer to yellow-green instead), and another new example is the Federal “Guard Dog” defensive load which also has a filled tip and it expands out into a hexagonal shape as the skived areas of the copper jacket open up and the polymer pushes out to fill the gaps which open up during the expansion process (nearly doubling the frontal surface area). If you really want to see some real world test results, one magazine published the pictures of where they reproduced the FBI barrier tests for the new Hornady Critical Defense rounds (which are similar to the Hornady Custom except instead of the XTP projectile these Critical Defense loads have the new FTX parked on the nose). The only barrier tests where the Hornady Critical Defense loads with the FTX projectile failed to repeatedly expand around 150% were the glass barrier test (windshield glass in front of the gelatin block) and the plate steel barrier (the bullet had to go through a piece of 1/4″ thick steel plate before hitting the gelatin block), and these two high barrier impact loads stayed somewhat close to the original diameter that the bullets started out, but all the other barrier tests were pretty predictable including the one for heavy clothes (the polymer-filled hollow point kept the hollow point from clogging with fibers and tearing through fibers which limit expansion). Yet another all-copper bullet was a Barnes version which utilized some polymer filling as well as the precut jacket segments which cover the hollow point almost totally were folded over each other to make a very controlled opening up of the jacket material, the polymer protected the cavity up front, and the copper petals of the jacket which were literally folded over into each other to form a very small opening on the front of the hollow point gave a very large and predictable expansion. But a quick run back to the ballistics charts tend to give relatively comparable values for all four of the most common calibers, with the .38 being the lowest and followed by the 9mm Luger, then the .40 S&W, then the .45 ACP (the value spreads among all four loads were not that great…..noticeable, but not a large amount), but I feel sure that once the four are pretty much balanced against each other then it would come down to the individual bullets parked on the noses of each. Either way, someone using FMJ’s is going to have an inhibited amount of potential energy transfer unless some hard object such as a bone is encountered. If the projectile continues on after impact, all remaining energy the projectile carries is lost from the energy transfer equation like it was never there to start with.

    Where on earth did Wile E. Coyote leave my Acme Rocket Skates ?????

  9. An excellent article, probably the best I have ever seen. I practice medicine and think I get pretty close to tissue and what makes it malfunction, so an opinion.

    To look for enormous statistical power in this kind of study is to expect too much; the author repeatedly says so. Nevertheless, it deals with real-world circumstances, not ordinance gelatin in an air conditioned lab or calculations from a physics professor. My point is ,”No way you can dismiss the data”, which some of you commenters did. If you click the corrected link to the main article, you will see his ANALYSIS of the data. Based on THAT(not the abbreviated CTD article), I think most of you would agree with him. He would acknowledge most of your concerns, in as much they are valid.

    You cannot dismiss the data, though. It is what it is! I shudder to think of how many medical studies do not have an overwhelming amount of statistical power, but we use them and use them to good effect. It certainly is a whale of a lot better than some goat roper’s opinion after a couple of long necks! So until someone invests several million dollars with supercomputers to sort out all (is that even possible?!) the variables, use what you got. THIS is a good and worthwhile article!

  10. My only qualification is being a 62 year old country boy who has shot a lot of guns and lots of critters. Number 1, LEARN TO SHOOT ACURATELY UNDER ALL CONDITIONS. Number 2, Carry a gun you will carry ALL the time. Number 3, All firearm are deadly in the hands of a competent, confident shooter. Number 3, A firearm you can’t access or shoot well will probably cause you more trouble than you can immagine. It matters not wheather .22 or .45, this old boy ain’t running out to catch any of them. I hope you never have to use it, but if you do, it’s best if there is only one story told.

  11. not exactly a qualitative study. way to many unknown variables here. it doesn’t take a rocket scientist to see the study is flawed, just look at the findings of a .22 being one of the most devastating rounds in the group. this like so many other so called studies amounts to nothing more than someones subjective opinion. I wonder why the FBI is not packing .22’s. the numbers are all over the place and have absolutely no value. whats the standard deviation, what were the circumstances in the shootings ie suicide, murder, accident, how was the incapacitating point reached (impossible to accurately measure unless it was one shot). are newspapers, magazines, and Internet the best sources for scientific information? is bullet placement taken into consideration or is it just assumed that all torso shots are created equal and the only variable is the caliber of the bullet. who wants to take the .44 mag gut shot and who wants the .22 gut shot, according to this “study” the .22 would incapacitate the attacker with fewer rounds.

  12. Amen Alan Adams! I too am a law enforcement officer and firearms instructor. Being around guns since childhood, I wouldn’t voluntarily stand in front of a .22 or a .45, but given the choice if I was going to be hit with one, I’d take my chances with the .22. The key is practice, practice, practice and not just paper targets at the range. Practice drawing from concealed carry and understand it’s a whole different world when you are under stress and in fear for your life or someone elses.

  13. This is one of the oldest (and most fun) debates in shooting. Hunters argue over caliber and bullet placement, self defense guys the same. All of the reasonable arguements come down to two, one, a 30/06 in the heart lung area is a better first shot on a lion than a .375 in the gut,and 2. a .22 is better than throwing a rock at an assailant. If you are good with what you carry you are better off than if you have nothing, or something you THINK is the right gun but you can’t shoot.

  14. A bit of my background: I am a retired law enforcement officer and also weapons instructor. I am an avid hunter and have seen numerous wounds in both humans and animals by many different calibers and types of bullets. My fear is that studies like this one will encourage people to rely on calibers that are by no means effective. Every situation is the bad guy you’re trying to protect yourself from under the influence of alcohol or drugs? Is he wearing a tee shirt or a heavy winter parka? I will play the percentages and carry the most powerful handgun that I can control and conceal. Will a .22 kill? You bet it will. I don’t want to be shot with anything, but if I had a choice of being hit with a .22 long rifle of a 230 grain quality hollow point from a .45ACP, I’d take the .22 every time. The bigger the bullet, the more tissue damage and the more tissue damage, the faster the subject will bleed out and stop fighting back. There is a reason why the .22 rimfire is not legal for deer hunting. If all you have at hand is a .22, by all means use it until its empty, but there are much better choices for self defense.

  15. long guns
    1 round from 12 gauge shotgun
    or first 3 rounds up to 24 rounds from a semiautomatic 10/.22 Ruger?
    at under 10 yards?
    whatever you’re comfortable with

  16. Unfortunately, this type of study is more relevant when using known factors – 10 people of identical height/weight,and clothing, shot at the same distance and direction of travel, same caliber etc. There are just too many variables here. The most confusing is the average number of rounds to incapacitation. Huh? Example: 5 men shot (all 9mm): 1 man took 4 rounds to stop, the others 1 round each. That is all you can say. Any average will be misleading, as no one man was ever hit with 1.6 rounds. And how was the incapacitation stat arrived at? Was each victim asked ‘at what hit did you stop attacking? Was the shooter asked at what round did the attack stop. Good study and effort (I tend to be a shot placement advocate myself) but the method is open to question.

  17. Great article on a great subject, “What caliber is best…best knockdown power…” I hear or am asked about [sufficient] knockdown power constantly. My answer is the same, “knockdown power means nothing to me. One shot stop or, shot placement IS YOUR knockdown power.” I hear students knocking the 9mm, “not enough knock down power. Especially if someone is wearing very heavy clothing…” My comment to those students, “If there’s not enough knockdown power in a 9mm. Would you let me shoot you with it? How about a .380 or .22lr? If you’d like, you can put on multiple sweatshirts and jackets and even wear my Kevlar vest. Do you think you’d be able to stand if shot in the chest?” Harsh way to put things? Yes, absolutely. However, it drives the point home. Shot to an assailant with a 40S&W in the forearm or, one shot perfectly placed to the head with a .22lr. Which has more knockdown power? Answer, the one the where shot placement was best. I’m a .45 guy but, not because of its “knockdown power” it’s simply the caliber I can place my shots best and quickest with.

  18. I carry a Walther P-22. I use a CCI .22 LR round that is segmented. One hit is equil to being hit three times. this round will penitrate to 8 – 9″ in jell. Three hit is like being hit 9 times.

    Thankfully I’ve nerver had to use my weapon for defence, but if i do I will not hesitate to do so.

    I qualified with a SW .40 cal for my Conceal Carry Permit, we were required to have 40 kill shots. I had 1 in the head and 39 in the upper torso. So I sure I will be even more reliable with a .22 with multiple shots. I always carry an extra clip.

  19. This seems to give more faith in small caliber shots to the torso area instead of trying/aiming for head shots – much easier in a stress situation.
    BTW – your link to the full report did not work for me.

  20. The results of the .22 cal. being effective is right on the money. There is a lot of surgeons out there, that will tell you that the lighter caliber of ammo carrying a smaller bullet will do more damaage than that of the larger calibers even with self defense rounds. For the simply reason is that most self defense takes place at a very short distance. The larger calibers will go in and out of tissue because of impact issues. However the smaller .22 cal. will a hit bone and bounce arround causing damage that is equal of many shots from the larger caliber pistol. It is also important for women that do not like or can control the recoil of the larger pistols. Thus missing the target. Because of their own fear of their own defense, they most likely will be hesitant in responding to a threat. Where the smaller caliber they will have more confidence in, regarding control of shot and recoil factors. I own large and small calibers. Will tell you that some of those small calibers are rather impressive.

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