What’s the best caliber?

It happened again. Someone asked me what I thought the best caliber is. Granted they didn’t ask it quite that ambiguous. But it did raise the “insufficient information hackles” when I got the email.

The actual question was:

Tell me which caliber you think is best and why:  9mm, 40 S&W, or 45 ACP.

Had the question been, “Which caliber has the best stopping power?” I would have replied, “It’s tough to beat something chambered in 200 mm XM422 with the 40 kiloton yield option”.

The question isn’t quite that unbounded but still it’s insufficiently bounded to give an answer that is credible for even a fraction of the possible values of the unconstrained variables. One must really have more information about the use cases of the firearm before you can give an answer that someone couldn’t drive a Euclid truck through.

When someone asks a question like this what you really need to do is get the person asking the question to answer it for themselves. For all intents and purposes they already know the answer they just don’t know the proper questions to ask themselves. You can help them with this.

The top level question is, “What are you going to use this gun for? Recreation, self-defense, competition, all of the above?” One could drill down to a depth of three or more in the specifics for any of the answers given but here are few of the possibilities:

  • What is your ammo budget?
  • Self-defense against two legged varmints or four?
  • What is the body mass of the varmint you need to defend against?
  • One attacker or a mob?
  • Which sport?

Everything is a tradeoff. The smaller calibers tend toward higher capacities, higher velocities, lower costs, and, obviously, smaller holes. With the larger calibers the opposite is true. Once you figure out your application then the caliber question should pretty much answer itself.

If you are interested in self-defense “stopping power” then I answered that question nearly 15 years ago and I don’t see any reason to update the conclusion where I agree with Greg Hamilton who says:

The entire discussion of “stopping power” is both stupid and irrelevant.   Statistics cannot be applied to individuals. People that need to be shot need to be shot soon and often. They need to be shot until they run out of fluid, brains, or balls.

If during the time you were reading the latest “stopping power” article you were instead practicing to save your life you would be far, far ahead.

Greg Hamilton
May 08, 1998

Of potential interest is what caliber gun(s) do I own and use and why.

I have guns in all three of the calibers in question. I almost never use the 9mm or the .45. The reason has nothing to do with the caliber themselves. It is because a .40 with 17 or 18 round magazines is the best choice for Limited class USPSA matches which I compete in. I can compete in USPSA and Steel Challenge with it and I can carry it for self-defense. I figure the odds of me using it in self-defense are pretty low but the probability of me using it in competition are near 1.0. And even supposing that some other caliber/gun would be better for self-defense the fact that I am going to be practicing with the competition gun is probably going to make up for the (questionable) fact that I wasn’t shooting the optimal caliber.


13 thoughts on “What’s the best caliber?

  1. Plus just about one thousand, Joe! Being able to shoot, and shoot well, is more critical to self-defense than what you are shooting. …Okay, I’d be a little worried with .22 or .25, but if it was all I could manage? Way better than nothing.

  2. There are two correct answers: “yes”, and “what you have at hand when you need it”.

    Or, to give the standard engineering answer, “it depends…”, as you noted. Everything IS a tradeoff.

  3. I like 10mm. It’s got the same ammo capacity potential as .40S&W, and I’m a really big guy, so I don’t feel like I’m operating below my potential by shooting something with less kick. And all things considered, I’m pretty good with it. Although I don’t practice nearly enough, and it’s kind of spendy.

  4. So essentially the .40 is your “only” gun.
    You practice with it the most, so really you are living proof of the “beware the man with only one gun” maxim.

    And as Roberta X alluded to, nobody wants to be shot with even a .25 acp.

    • It’s the “only” (there are some extremely rare exceptions) handgun I carry on my person.

      I select from three (sometimes more) different rifles depending upon the distance to the target and the application.

  5. I carry both 9mm and .45 for different reasons, I also have a .357 sig (with .40 barrel for practice) that sees occasional use. It just depends on my use case at the moment. There is no best round, only a “best round” for a given situation, and most of the factors that lead to that determination are subjective.

  6. Really good analysis, Joe. Which boils down pretty much to:

    .45 ACP – best caliber on planet earth, for any reason, in any platform.

  7. Pingback: SayUncle » What’s the best caliber for . . .

  8. Having the gun on you is what is important. The rest is just conversation.

  9. If I could find ammo I trusted to go bang every time, I’d carry my walther p22 (5 inch barrel version). Because I’m more accurate to greater range with that than any other handgun I own. Multiple vision issues (cross eye dominant, astigmatism, and that’s just a start) creates a limit to my ability to line up sights, but something about that 22 just works for me.

    Of course, it could be that I’ve got better than 10k rounds, at an estimate, through that gun. Easily five times as many as anything else I own.

  10. Yep, as always it’s about tradeoffs, I got asked the same question, but I answered it a slightly different way, since I carry either a 9 or a 45 depending on circumstances.

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