Are .32's the best caliber for self-defdnse?
The short answer is, for a snub nose or other small-ish frame revolver, yes.
The long answer, because I don't like giving short, simple answers to questions without supporting them with reasons, is that while a larger caliber is usually better, that doesn't mean that smaller calibers are useless, and this holds especially true for handguns. Too many are obsessed with a One Master Caliber Solution (OMCS). For revolvers it's .38/.357 and for semi auto's it's 9mm and to a lesser extent .45.
The issue with the OMCS is the person is stuck in a mindset that any other caliber that is not their Master Caliber is bad and will not allow themselves to accept believing that the Master Caliber is not the best because once they accept it's not the best they have to seek the best and that involves spending money on new guns, possibly loading equipment, etc.
The facts are that the smaller the gun, the more difficult it will be to shoot as caliber increases. The solution then is to put a smaller caliber in a smaller gun, a larger one in a larger gun. The advantage is the smaller caliber allows the smaller gun to utilize its advantages while not exposing its weaknesses. In that I mean that a .32 or a .357 in an N frame is a ridiculous waste of potential compared to what a .44 Mag has. That's not to say everyone should be carrying a .44 Mag now because that's impractical, but there is little reason to conceal carry a 5 shot Model 69 Combat Magnum in .44 over a 7 shot 686+ in .357 Magnum if you're not expecting to encounter dangerous bears or the like.
The science shows that .357 is effective against people.
So if it's not worth going up in caliber, why is it worth going down like .357 to .32/.327? Because the smaller revolvers shoot easiest with a smaller caliber and they are also effective against people.
The same goes for 9mm in semi autos. I think 9mm is great for single stack compacts and Sig P365 type pistols, but for a full size doublestack, the .40 and 10mm rule and outperform 9mm and .45 ACP. For even smaller guns than compacts like the LCP, it's just like the snub in that the .32 has the advantage over the .380, smaller caliber is better caliber for the smaller gun, however the correct .32 to use in that size gun is one that is horribly uncommon and the parent case for it was .380. Until .32 NAA becomes more common, the .32 and .380 ACP are the only two options for micro semi auto pistols and between those two options I can shoot .32 ACP far better than I can .380 and while .380 hollow points have come a long way, they're still questionable.
