In response to a question about what calibers to use for self-defense, the venerable Jeff Cooper once said something along the lines of, “Use the biggest caliber you can shoot well.” He had other qualifiers, but that is the important part for this article. He did not live through 2020, but the sentiment and fact remain the same.
That, of course, does not mean .460 S&W is the best choice for concealed or open carry if you can manage to shoot it well. There are concerns like your hearing (and that of the innocents within a city block), massive over-penetration, and being vilified by a District Attorney. A gun-unfriendly DA may well consider it overkill/excessive force/”Ramboism”… and then, the process becomes the punishment. (Please understand, that doesn’t mean a .460 S&W is always the wrong choice either.)
If I am on a bear hunt in Alaska, a six-inch barreled .460 might be the appropriate sidearm. The reason for carrying that revolver would be “in case of bear surprise.” It is not my fault that the surprise I got was a couple of furless bears in human suits. Their attempt to jack my truck deep in the woods may make my use of an “overkill revolver” quite justified. If the situation is there is no one else within 20 miles and two slovenly guys comment on how nice “their” new truck is. One guy has a baseball bat and the other guy has already started digging a hole with his shovel. I think I can articulate my choices quite well to the DA.
Having said that, in normal suburbia circumstances, the common choices in calibers are .380 ACP, 9mm Luger, .38 Special, .357 Magnum, .40 S&W, and .45 ACP. In order to forestall the hate mail, other calibers might include 10mm Auto, .357 SIG, .327 Magnum, and .32 ACP. Other even less common calibers might include .25 ACP, 9×18 Mak, .22 Magnum, or .22 LR. We will focus on the first six in some detail, then discuss some of the others from the “con” position.
The rules for the discussion: these are my opinions. Backed by fact where I can, but they are opinions, treat them as such. We are using probabilities, not the rule of one (rule of one definition — just because it happened once, doesn’t make it the way to bet). You are welcome to choose whatever calibers you like. Just know, choosing .25 ACP is a far less common (and less effective) choice FOR A REASON.
I am not a lawyer. This is not legal advice. Carrying and not carrying are both potentially dangerous, so is reading this article if you are a fanboy of any particular caliber’s evangelical awesomeness. You have been warned.
Calibers To Consider
I carry 9mm Luger in my fairly modified Smith and Wesson M&P. I consider this to be one of the best 9mm pistols. I also carry 9mm (0.355”) in a Kel-Tec PF9 as a backup gun (BUG). I carry .380 ACP (0.355”) in my Kel-Tec P3AT and for those times when concealed really needs to mean concealed.
My girlfriend carries .40 S&W (0.40”) in her duty weapon (Glock 22). For off-duty, she either carries 9mm in her Glock 17 or her Glock 43. Her usual choice is the G43, as she is small and it is much more concealable on her. She is frequently with me, so our combined load-out is, usually, at least my full-sized M&P with two backup mags and her Glock 43 with one backup mag. Our primary choice for carry is obviously 9mm Luger.
Within the 9mm realm, I carry the Federal 150-grain HST Micro in the M&P. In the PF9 and Glock 43, we both carry the Barnes 115-grain TAC–XPD +P. The question becomes, why do we choose 9mm and why do we choose those particular bullets? The answers:
In the full-sized guns, independent testing shows the Federal 150-grain HST Micro produces (in gel) an average penetration of 17-inches with 0.71-inch of bullet expansion, with an average velocity of 900 fps. This is at the upper end of the FBI penetration parameter and is also at the upper end of the bullet expansion matrix for available 9mm ammunition. The heavy-for-caliber projectile helps with penetration, and the slightly low bullet velocity helps with recoil mitigation and speed of follow-up shots. We use this both in the M&P and the Glock 17 to good effect.
For the smaller-barreled guns, we use the Barnes 115-grain TAC–XPD +P. Our personal testing has shown the above round performs well in our BUGs. The lower velocity of the shorter barrels does impede performance in comparison to full-sized guns. The reduced performance is not as diminished as it is for the Federal 150-Grain Micro. The Barnes velocity drops, but it starts out much quicker, so the expansion is less affected. We do not get the optimal 0.70 inches that we get from our full-sized guns, nor the 13.5 inches of penetration, but we still get an average of 0.55-inch expansion along with just under 12 inches of penetration.
In our limited testing, this seems to be the best performance compromise. The round is also quite controllable in the smaller platforms. In comparison, a former choice of mine the 135-grain Hornady Critical Duty. From a full-sized gun, it produces an average of just under 19 inches of penetration, with 0.45-inch expansion at 1,050 fps. Another former choice, the 124-grain Speer Gold Dot +P shows just under 17 inches of penetration with 0.51-inch expansion at 1,150 fps. Those numbers would be much lower for our shorter-barrel options.
In the Glock 22 (.40 S&W), she has no choice but to use issue ammo. Her agency issues 180-grain Speer Gold Dot, a solid performer at 14.5 inches penetration with 0.65-inch expansion (unlike the 165-grain with 27.1 inches penetration and no expansion) for non-patrol officers. As an SRO, she is still issued a .40 S&W. The patrol officers have transitioned to 9mm.
If I was in charge of purchasing for her agency, I would likely choose the Winchester 165-grain Ranger Bonded. The Winchester is VERY consistent in both expansion and penetration. The deviation in penetration was less than an inch from deepest to most shallow. The expansion also varied very little and was quite large, at an average of 0.77 inches. Also, the 165-grain projectile is a bit more recoil-friendly for faster and more accurate follow-up shots than most of the similarly performing 180-grain options.
My choice of .380 ACP ammo for my P3AT is the Hornady 90-grain FTX Critical Defense. This is one of the few ammo choices that performed well both for penetration and expansion. The test showed 13.2 inches of penetration and 0.52-inch expansion.
In comparison, most other options either gave good penetration, Remington 88-grain HTP with 16.8 inches, but had almost no (0.36-inch) expansion, or had good expansion, Winchester PDX-1 at 0.63-inch, but had poor penetration, average of 9.5 inches. These tests used the shorter barrel of a Glock 42.
In a complete act of HERESY, the only .45 ACP (.0452”) platform I own is an AR. This means I do not have a “go-to” choice for .45 carry ammo, but if I did, here would be some of my thoughts.
The Winchester Ranger T-Series, the 230-grain Ranger T and Ranger T +P both perform at the absolute top of the expansion range at 1.00-inch and 0.99-inch respectively. They also perform well in penetration, with both running consistent averages of 14.5 inches.
The Federal HST and HST +P also perform well. Expansion averages 0.85-inch and 0.79-inch, with consistent penetrations averaging 14.0 inches and 14.9 inches. As with the Ranger T-Series, I do not see the advantage to the extra recoil of +P, as the lower pressure rounds expand more and had little penetration handicap.
Calibers To Question
There are choices that perform very poorly when it comes to self-defense. The Liberty 78-grain (yes, a 78-grain .45 ACP), despite its blistering 1,850 fps initial velocity, can only manage 10.9 inches of penetration and almost no expansion (0.47-inch) and did not retain over 90% of projectile weight.
In a surprise to me, the Remington Ultimate Defense 230-grain had 23.9 inches of penetration but no (0.45-inch) expansion. I should also note, the Winchester Ranger Bonded (not the Ranger T-Series) did not perform consistently. Penetration ranged from 17 inches to 30 inches and expansion ranged from .048-inch to .065-inch, for an average of .056-inch.
.38 Special / .357 Magnum
For those of you who run revolvers, the .38 Special and the .357 Magnum calibers (both .0357″) are the most common choices. The next issue is what barrel length to utilize. The most common carry choice would be something like a Smith and Wesson J-Frame with roughly a two-inch barrel.
Most people these days who choose to carry a four-inch gun will run a semi-auto of some sort. My only revolver in this caliber area is a 5.5-inch, N-Frame Model 27. She does NOT see carry duty, but the load I choose to run is the 125-grain Speer Gold Dot in .357. My numbers are likely better from a 5.5-inch barrel, but the four-inch numbers are 1,427 fps, .054-inch expansion, and 19.3 inches of penetration.
For comparison, the same choice in a two-inch barrel produces 1,200 fps, 0.36-inch expansion, and 29.3 inches of penetration. As you can see, zero expansion and way too much penetration. This would be a poor choice for a snub nose.
As a general rule, .357 produces lots of extra recoil and muzzle blast for no increase in performance until you run at least a four-inch barrel. The extra powder just doesn’t have enough barrel to make a useful difference. If you just have to run .357 in your snub nose, there are better choices.
The Barnes 125-grain TAC–XPD runs 1,250 fps with 0.75-inch expansion and 14.2 inches of penetration. The Barnes 140-grain XPB VOR-TX, Buffalo Bore 125-grain with the Barnes 125-grain SPB short barrel, and the Federal 140-grain Barnes XPB all perform well. You may notice a pattern with those choices. For most of us running a snubbie, the proper performance-to-recoil ratio is going to be found in .38 Special loads.
For those needing the lowest recoil, the Hornady 90-grain Critical Defense Lite gives decent performance (very good considering the projectile weight and super low recoil) at 896 fps, with 0.43-inch expansion and 11.8 inches of penetration. The four-inch barrel increases velocity by 100 fps, but decreases penetration by an inch with the same expansion.
The best performance is from the Federal 130-grain Micro HST at 824 fps, with 0.73-inch expansion, and 13.0 inches of penetration. I have not shot this load, but it should be mild in recoil as well.
Moving to a four-inch barrel gun increases velocity by 30 fps and penetration by just over an inch, with similar expansion. The minimal increase in velocity means most of the powder has burned in the two-inch barrel, so muzzle blast should be low in either barrel length.
The Remington Golden Saber 125-grain +P provides 877 fps, with 0.62-inch expansion and 13.9 inches of penetration. The four-inch barrel increases velocity by roughly 130 fps, so a fair amount of powder remains unburned in the two-inch barrel. This will create a fair amount of muzzle blast and excess recoil. Most +P .38 Special rounds will be this way and should perform best in the four to eight-inch barrel length.
The penetration decreases by almost 1.5 inches and the expansion drops a tad to 0.59-inch in the longer option. This is likely a result of a soft bullet intended to begin expansion at slower velocities. It has likely expanded to at least the 0.62-inch mark and peeled back to a smaller diameter due to excess velocity.
Calibers To Avoid
I am going to give a small amount of information regarding the calibers that I think have VERY little place in the self-defense role. These calibers are (in order of worst to least worst) .25 ACP, 9×18 Mak, .22 LR, and .22 Magnum.
The .25 ACP’s only advantage is it normally comes in a tiny gun that is easily concealed. Most of those guns have names like Raven or Jimenez, and are known for being just as likely to harm the shooter as the target.
The other joke is (for a very good reason) “I will beat a guy to a pulp if he shoots me with a .25 ACP and I ever find out about it.” This caliber provides poor penetration, no expansion, and normally comes in a rattle-box gun.
This may be the exception that proves rule number one of a gunfight, bring a gun. You only think you have a gun with most .25 ACP choices. No bullets tested have significant expansion and none had consistent penetration to the 12-inch mark.
The 9×18 Mak has most of the components needed for successful carry. There are plenty of decent guns. The velocity is there, the real issue here is there is not much choice in appropriate self-defense ammo.
Most of what is available is ball or non-expanding. This creates strong over-penetration and a distinct lack of stopping power. Please realize this is not easily fixed by reloading, as the bullet diameter is .365”, not the .355” of the more common 9mm Luger.
The Hornady 95-grain FTX is an example that could work well, with 13.5 inches of penetration and 0.46-inch expansion. It is on par with the low end of the middle of the pack for 9mm Luger rounds.
Many people choose .22 LR, and for those with severe arthritis, it has its place. Some people will also choose a .22 LR NAA revolver as a BUG. This does fulfill the first rule of a gunfight. Just realize that you are essentially shooting ONE pellet from a #4 buck load at someone. Most #4 buckshot has 27 (or more) pellets. The combination of being hit by most of those pellets is what stops the target. A single one CAN, but it isn’t the way to bet. If .22 LR is all you can run, make sure you train to shoot several rounds for increased effectiveness.
One advantage .22 LR has over a single #4 buck is it is heavier. The #4 buck is about 20 grains, whereas the .22 LR typically runs from 30 to 40 grains, with some up to about 60 grains. The extra weight will help with penetration. Be aware the 60-grain options will not stabilize in many pistols and may fail to cycle the bolt in a semi-auto.
Of the choices tested, from a two-inch barrel, the best performer was Winchester Varminter 37-grain HE. It provided 0.25-inch expansion and 12.7 inches of penetration. Not exactly stellar, but most other choices had no expansion and often less than 10 inches of penetration.
Our last discussion choice is the .22 Magnum. For those who are very recoil adverse, this is a potentially better option than .22 LR. Like with the revolver choices, here barrel length makes a big difference. Almost all options performed better than .22 LR, but using a +four-inch barrel (like on the Kel-Tec PMR-30) greatly increased performance.
Hornady 45-grain Critical Defense provided 0.37-inch expansion and 12 inches of penetration with a two-inch barrel and 0.40-inch and 13.6 inches, respectively, with the longer barrel. Speer 40-grain Gold Dot also performed well at 0.33-inch and 12.9 inches from the short barrel and 0.42-inch and 14.7 inches from the longer option. Neither is what I would call optimal, but considering the platform size, the minute recoil, and the diminutive round, this is fair performance.
If you are using the Kel-Tec PMR-30, having 30 rounds can make a large difference. Even a five or six-shot revolver will take the starch out of most attackers.
Conclusion: Self-Defense Calibers
You now have more information on calibers than you likely had before reading the article. You are hopefully better informed and are free to flame me on why .25 NAA is the best self-defense round ever. Just be aware, I will quietly (or not so quietly) laugh at you.
What are your favorite self-defense calibers and why? Let us know in the comments section below!
Editor’s note: This post was originally published in February of 2021. It has been completely revamped and updated for accuracy and clarity.