The argument over prioritizing between caliber and capacity when carrying a pistol for self defense is quite possibly the most polarizing topic among gun aficionados. In fact, I have spent many hours discussing this very topic with various friends and have mentioned this something to consider when selecting a handgun for concealed carry. But at the end of the day, it’s a personal decision that comes down to what is right for an individual.
So how does one ensure they’ve made the right decision for themselves? Wish I could answer that, but I’m not sure I can answer that question for anyone other me. So that’s exactly what I will do here.
If you’ve been reading my ramblings for a bit, you probably know that my every day carry is typically a 9mm Sig Sauer P229. At the core of this carry choice, the P229 is a gun that I can afford to shoot, a gun that I can and do carry just about about anywhere I legally can, and a gun that I shoot well. When it came to considering caliber and capacity, there were several things I considered when considering the most typical potential threats I may encounter.
I live in a city with a population of about 1 million and I tend to find myself where humans tend to out number dangerous wildlife. Given those parameters, suitable potential cartridges included .380 ACP, 9mm Luger, .40 S&W, and .45 ACP. When it came down to it, I settled on 9mm primarily because it’s the caliber I am most able to shoot out of that set. I find that I am able to shoot .380 ACP and 9mm equally well and 9mm is the most powerful out of those two. In this case, I measured my ability in terms of being able to accurately place shots in combination with being being able to quickly accurately place follow up shots. While I can place initial shots equally well with .40 S&W and .45 ACP, I can place accurate follow up shots faster with 9mm than I can with .40 S&W or .45 ACP. I suppose one could say all else being equal, I prioritized power of the caliber over capacity when it came down to 9mm or .380 ACP – although I think that is a no brainer given capacity between those two is essentially identical given the similarity between the diameter of those cartridges.
Would the same be true if I was picking between 9mm and 45 ACP? No.
Given my typical surrounding environment, capacity does come into play. I’ve read various statistics published that it takes an average of 2.45 hits to incapacitate a human threat and about 5.55 shots to make a hit which puts us at about needing about 13.6 rounds of ammo to stop a single threat. Those same statistics indicate most self defense situations do not involve multiple attackers, there is still about a 1 in 5 chance your will encounter multiple attackers. With those odds, I opt to carry a minimum of 28 rounds. With that in mind and assuming equal shooting ability between all calibers, I find that in a self defense situation larger calibers will require additional reloads and reloads increase time between shots fired. Not to mention larger calibers mean more bulk and weight to carry around due to bullet weight and additional magazines.
To reiterate my ramblings in a more coherent manner, in the caliber versus capacity debate balance between the two is most important to me. Assuming everything else is equal, a larger caliber is more important until reaching a caliber suitable for the threat I am most likely to encounter; then capacity becomes more important. This is why I opt for a Sig Sauer P220 in 10mm Auto as my side arm when going on a hunt and a Sig Sauer P229 in 9mm for every day carry when I am not hunting.

