In defense of larger handgun calibers

In the wake of the spate of recent terrorist and criminal incidents, I’ve again been getting queries about what cartridge or caliber is ‘best’ for self-defense.  In particular, some folks with what they consider to be ‘old-fashioned’ heavier-caliber weapons are asking whether they need to go to lighter caliber equivalents that can hold more ammunition.  Whilst there are definitely factors that favor such a switch, there are others that motivate against it.

I’ve written extensively about this in the past, and I don’t want to re-hash everything here;  but for the benefit of those who may have missed earlier articles, I’ll provide a brief summary.  See these previous articles for more in-depth information:

In recent years a number of law enforcement agencies and other authorities have concluded that ammunition performance in smaller cartridges such as 9mm. Parabellum has improved to the point that they offer performance almost as good as traditionally ‘superior’ cartridges such as .45 ACP, .40 S&W, etc.  The FBI, which inspired the development of the .40 S&W after the infamous ‘Miami Massacre‘ incident, has decided to switch back to the 9mm. for this reason among others.  Other important factors are that many (perhaps most) shooters find the recoil of the 9mm. round easier to control than its bigger brethren, and also that pistols using the smaller round can be made physically smaller, thus enabling those with smaller hands to use them more easily.

Nevertheless, larger rounds retain a significant advantage in terms of bullet momentum and its resultant effects on the target.  I discussed momentum in the third part of my ‘Myth of handgun stopping power’ series;  please read the discussion there.  Briefly, momentum (and hence depth of penetration) is generally improved with a heavier bullet, while velocity (and hence bullet energy) is generally improved with a lighter bullet.  (That’s an over-simplification, but in a brief overview like this, it’ll have to do.)

Whilst maximum energy delivery on target is an important aspect of a defensive round, momentum has a value all its own when it comes to penetration.  Examples include the need to penetrate concealment such as vehicle bodies, or deal with heavy-set attackers (i.e. having greater volumes of flesh and hence distance to penetrate between their skin and their vital target zones), or get through heavy outer clothing such as multiple layers worn in colder climates.  A round with greater momentum will generally penetrate more easily, and penetrate deeper into, such targets.

There’s also the issue of the shock delivered to the target.  I think it’s unquestionable that a heavier bullet, with greater frontal area and momentum, will deliver a greater initial shock to the target.  I offer two real-world tests that you can conduct for yourself.

The sport of bowling pin shooting has become very popular over the years.  Briefly, the shooter engages a table full of bowling pins and attempts to not just knock them down, but drive them off the table, as fast as possible.  Here’s a video clip demonstrating the sport.

There are classes of competition for smaller, less powerful cartridges, even down to the lowly .22 Long Rifle (using smaller, lighter targets, of course);  but in general, for the same size and weight of bowling pin, a larger, heavier, more powerful cartridge will be more effective than a smaller, lighter, less powerful one.  Try this for yourself.  Set up a big, heavy bowling pin on a table-like surface six feet in depth behind the bowling pin.  Shoot at it with both a heavier and a lighter caliber, using the same point of aim.  (I suggest .45 ACP and 9mm. Parabellum, two of the most-used defensive cartridges.)  See which one knocks it down more easily, and drives it further back down the surface.  See which one knocks it right off the rear of the surface more quickly.  I think you’ll find that the heavier cartridge does better than the lighter one, almost all the time.

The second real-world test is hunting.  Many hunters have shot game animals roughly the same weight as (or sometimes heavier than) human beings with handgun cartridges.  All too often, rounds that are very highly rated for self-defense against humans don’t do well at all against such animals.  One of my favorites, Winchester’s RA9TA 127gr. 9mm +P+ round, did very poorly for my friend Lawdog in an encounter with a wild hog.  (On the other hand, so did a .45 ACP round from the next officer to arrive on the scene.)  Jim Higginbotham, a firearms instructor and active shooter with decades of experience whose views I respect very highly, reports that the fabled 125gr. .357 Magnum round, beloved of experts for many years, has performed very poorly on deer in his hands, as have many 9mm. rounds.  On the other hand, he’s used .45 ACP on deer with good results.  (Admittedly, whitetail deer are generally a lot less tough than wild hogs!)  My own favorite cartridge for handgun hunting (not that I do a lot of that these days, since my disabling injury) has long been the Federal 300gr. CastCore load in .44 Magnum.  In general, larger calibers and cartridges have performed better on human-size and -weight animals than smaller ones.

This is not, repeat, NOT, to say that a 9mm. pistol or .38 Special revolver can’t be a perfectly satisfactory means of self-defense against a human being!  They most certainly can, particularly when loaded with an effective round that’s accurately directed against a suitable target zone.  I carry such cartridges almost every day, and I’m comfortable relying on them.  However, I also accept that they have their shortcomings, some of which we’ve discussed above.  I saw those shortcomings magnified in actual combat in southern Africa during the 1980’s (admittedly with earlier-generation ammunition that wasn’t as advanced as modern versions), and I therefore remain more comfortable with larger, heavier, more powerful cartridges than I am with smaller, lighter, lower-powered alternatives.  When I’m carrying the latter, I expect to have to use more rounds to achieve the same results that I would with fewer rounds of the former.

Jim Higginbotham’s comments bear repeating.  I endorse them from my own experience (which, I hasten to add, is far less than his!).

Your skill is far more important that what you carry, within reason. We are not really talking about “stopping power”, whatever that is, here but rather effectiveness.

I can find no real measure – referred to by some as a mathematical model – of stopping power or effectiveness. And I have looked for 44 years now! Generally speaking I do see that bigger holes (in the right place) are more effective than smaller holes but the easy answer to that is just to shoot your smaller gun more – “a big shot is just a little shot that kept shooting”. True, I carry a .45 but that is because I am lazy and want to shoot less. A good bullet in 9mm in the right place (the spine!) will get the job done. If you hit the heart, 3 or 4 expanded 9mms will do about what a .45 expanding bullet will do or one might equal .45 ball . . . IF (note the big if) it penetrates. That is not based on any formula, it is based on what I have found to happen – sometimes real life does not make sense.

. . .

In real life, your gunfight may be dark, cold, rainy, etc. The subject may be anorexic (a lot of bad guys are not very healthy) or he may be obese (effective penetration and stopping power of your weapon). There are dozens of modifiers which change the circumstance, most not under your control. My only advice on this is what I learned from an old tanker: “Shoot until the target changes shape or catches fire!” Vertical to horizontal is a shape change, and putting that one more round into his chest at point blank range may catch his clothes on fire, even without using black powder.

We tell our military folks to be prepared to hit an enemy fighter from 3-7 times with 5.56 ball, traveling at over 3,000 feet per second. This approach sometimes worked, but I know of several cases where it has not, even “center mass.”

With handguns, and with expanding bullets, it is even more unpredictable, but through years of study I have developed a general formula, subject to the above mentioned unpredictable circumstances.

  • 2-3 hits with a .45
  • 4-6 with a .40
  • 5-8 with a 9mm

With a revolver, the rounds are not necessarily more effective but I would practice shooting 3 in a .38 or .357 merely because I want 3 left for other threats. Not that those next three won’t follow quickly if the target hasn’t changed shape around my front sight blade. A .41, .44 or .45 Colt I would probably drop to two. Once again, they are not that much more effective than a .45 Auto but I don’t have the bullets to waste.

In any case, I want to stress the part that it is more about how you shoot than what you shoot, within reason. It is also more about the mindset and condition of the subject you are shooting which is not under your control. Take control – buy good bullets and put them where they count the most! And remember “anyone worth shooting once is worth shooting a whole lot!”

There’s more at the link.  Sage advice, and worth following, IMHO.

I hope this discussion has helped to clarify the situation.  Don’t rely on my words alone!  There’s an immense volume of material out there.  Read widely, and learn from as many sources as you can.


EDITED TO ADD:  In the light of feedback from readers about this blog post, I’ve written a follow-up article, which may be found here.


  1. The bigger the hole, the faster all the crazy leaks out….

    One thing that the people who champion the new-and-improved 9mm never seem to mention is the same improvements in bullet design ALSO apply to the larger calibers. It's comparing apples to oranges if you say a modern 9mm bullet is vastly improved relative to .45 hardball.

  2. I feel blessed that the 1911 45 is, of the few pistols I have fired, the most ergonomically perfect for my physique. The effectiveness of any weapon choice is a complex of power and precision versus mass and uncertainty. The salient point, a 50 caliber to the earlobe is rather less effective than a 22 to the eyeball. Shoot the largest heaviest round you can comfortably and reliably place on target. The uncertainty with people is the surface changes. For the common encounter with a mugger or idiot in a nightclub with an AK any solution properly delivered will work. body armor changes the question but no magic bullet is a substitute for accuracy.

  3. IMHO, the 40S&W was a poor compromise between the energy of a 45ACP and capacity of the 9mm. Most people will shoot better qualification scores with a 9 or 45. Yes you can load down a 40 S&W for games like USPSA, but for defensive shooting that's a feature without benefit.

    Your mileage may vary.


  4. Depends. With the proliferation of body armor on the filth, a high cap pistol with a good trigger and sights may become more important, if they have to be hit in the head, neck or pelvis to do any good.

  5. I'd be interested to see if there's a difference on the bowling pin test if you load the two for equivalent energy (that is, reduced velocity on the larger diameter round and/or increased velocity on the smaller, lighter round). I'd expect them to be the same. I'd also expect penetration to be significantly less on the larger round with equivalent energy, as it would have more surface area to dissipate the energy into per unit depth. Of course, that's generally what you want – all the energy from the round being absorbed into the target. Fragmentation of the round and deflection would also be interesting to look at. We know from practical experience that big, slow rounds like .44 Magnum do better in heavy brush and undergrowth than lighter, higher velocity rounds with similar energy.

  6. Classic Texas Ranger reply to being asked why he carries a 45… "Because they don't make a 46."
    Not sure if it's true or not, but it makes a great story, doesn't it ?

    – Charlie

  7. The tests they do on handgun ammunition with expanding bullets shows that the different calibers all perform about the same. That said, they all perform about the same because they were designed to – ammo makers use the same standards, e.g., 12" – 18" penetration into ballistics gelatin. So, the self-defense ammo calibers of course give similar results. If we are talking about old fashioned hardball there still is a big difference in what the bullets do.

  8. "Of course, that's generally what you want – all the energy from the round being absorbed into the target."

    This sounds like a crock to me. I want the bullet to stop against the skin on the far side of the body, and smash every bone and organ it touches along the way.
    Yeah, I know, that is asking for the moon, to some extent. We are talking about handgun ammo.

    However, this term of "absorb the energy" makes little sense. How is that supposed to be useful? As an engineering term, it has no definition in this application. Sounds like more of a marketing phrase. I'm really tired of seeing it.

  9. And this:

    " We know from practical experience that big, slow rounds like .44 Magnum do better in heavy brush and undergrowth than lighter, higher velocity rounds with similar energy."

    And tests show that nothing less than cannon rounds ignore grass and light brush. Forget handheld weapons for this sort of thing. Make sure your bullets touch nothing but clean air, period.

  10. This sounds like a crock to me. I want the bullet to stop against the skin on the far side of the body, and smash every bone and organ it touches along the way.

    I'll agree with that, except…..there is only so much energy a human can absorb; small bullet moving fast, large bullet, moving slow, everything in between, all have "energy numbers" which we interpret on some kind of scale to provide "information" on how effective caliber X with bullet Y will be in situation Z.

    Will is, in ideal cases, correct: the bullet forming a bulge in the opposite side skin having damaged and/or destroyed everything it contacts in its path is the perfect result. Achieving that, however, is a statistical anomaly. Not that it shouldn't be the goal.

    Given that striking bone and passing through several organs of varying density requires a certain minimum amount of energy, I have absolutely no problem in applying more, and lots more if possible, energy to the target. If my projectile can break bone – fast and hard, to produce shards and fragments to do more damage and overstress the nervous system – and very rapidly destroy the functioning of critical organs to add to the overstress, I have no problem with that projectile exiting the other side, other than the usual concern about innocents standing behind the subject of my attention. As long as I have applied the maximum amount of energy the target can absorb, in such a manner as to maximize the absorption rate, I've done about all I can with a man-portable tool.

    The alternative to applying the maximum absorbable energy to the target is called "head shots." Start practicing them at 40 yards. Walmart sells 6 inch dessert plates; when you can go 6-for-6 in 10 seconds at 125 feet you're getting close.

    Pro tip: My older students have shown a preference for slide-mounted red dots, although there are good mounts for red dots that don't attach to the slide. And, if you're not using a timer you're "practicing" not "training." One needs measurable results against which improvement – or decline – can be measured.

  11. Still like my old Ruger P-89 9mm with the 15 round magazine and hot self defense rounds. The old gun has never jammed and I can place round after round just where I want them to be.

    However, when push comes to shove I'd probably have to rely on my little LCP in 380. It's such a small and compact gun that I can always have it with me. The 380 in the hand beats the .45 back in the gun safe or tucked away in the car's dash.

  12. A microcosm of gun enthusiast social media argument, right here.

    Peter, I recall that you were going to try carrying an XDS 45 for a while. How's that working for you?

  13. RE:

    2-3 hits with a .45

    4-6 with a .40

    5-8 with a 9mm

    Seems to me that this chart pretty much annulled the argument that the 9mm is better because it allows more magazine capacity – to respond to two assailants, one will need all of them.

    Ed "Hipshot" McLeod

  14. Regarding the term "absorb the energy", what it means is that the entire point of a projectile is to transfer energy from a weapon to the target. Breaking bones and destroying organs is accomplished through that energy transfer. The projectile has a certain amount of kinetic energy, which can be calculated with a relatively straightforward analysis of mass and velocity. A small, slow round may transfer all the energy from the projectile to the target and still do little damage simply because the energy per projectile is too low. Conversely, a large, fast projectile with lots of energy may still do little damage if the round flies through the target without hitting anything major – in this case little energy is transferred from the projectile to the target even with plenty of energy available.

    The whole point of modern projectile design is to come up with a bullet that both has sufficient energy and will transfer a sufficient amount of it to the target to be effective. Expanding bullets are the prime example for that, as it maximizes the surface area available for energy transfer and makes it more likely that all the energy will be transferred/absorbed by the target vs. wasted due to overpenetration. If expanding bullets are not available, wide, slow designs will outperform small, fast designs for the same reason – more energy is transferred to the target, less is wasted, even if they have the same energy.

    It really is just physics, and the terms do have useful, applicable meanings.

    What Will is pointing out is that you really want both sufficient energy in the round (breaking lots of bones/organs and penetrating through the body) and for the target to absorb all energy (stop against the skin on the far side of the body) for the perfect scenario.

    Regarding ignoring light brush and grass – cannon rounds don't do that either. All projectiles will be deflected by what they go through, and ignoring other factors such as shape, etc., a more massive round will be deflected less than a lighter round going through the same obstacles. A .44 will be better than a .22, and a cannon will be better than a .44 for the same reason.

  15. What we need is a small diameter, lightweight bullet – say, a 5MM – that exits the muzzle at very high speed, but due to its low weight offers low recoil, and upon contact with the target magically increases its weight to >500 grains and its caliber to 1.0"; mass, velocity and surface area are the keys, and I wouldn't turn down a good accuracy component, either.

    Lacking that sort of alchemy, we'll just have to make do with, hopefully, ever-improving bullet design, especially in major calibers, and sufficient propellant capacity to transform velocity into energy, plus some effort devoted to shot placement.

    As I side note, some years back, Speer used to make some half-jacket semi-wadcutters out of thick copper jackets and swaged lead: 240 grains in .429, an HP SWC version at 225 grains, and a 160 grain SWC and 146 grain HP SWC in .357. The swaged lead was soft enough to deform well and the thick jacket held most of the bullet together. Didn't feed well through lever rifles because of the soft swaged lead, but in revolvers it was great on deer and quite accurate. Methinks it would be just as successful a round in other pursuits. No idea why Speer dropped it from the catalog.

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