I've been searching out stories of citizens using firearms for protection, and over the past few weeks have read a couple hundred. Most don't specify the caliber of weapon used, but some do. And what I've noticed is there seems to be little, if any, correlation between the caliber of the weapon and the outcome. Almost all of the stories fit into one of these scenarios.... 1. Intruder entered house, citizen drew gun, intruder ran. 2. Intruder entered house, citizen shot, wounding intruder, he ran, cops caught him a couple blocks away or when he went to the hospital. 3. Intruder entered house, citizen shot, killing the intruder. In virtually all of the cases, drawing a weapon, whether or not fired, regardless of caliber, including .22s, stopped the attack. And there were as many .22 shootings that ended in death as any other caliber except a shotgun.
It seems on forums like this the accepted truth is that bigger is better, and most put the minimum acceptable caliber at a 9mm or maybe a .380. Now I understand that all things equal, a bigger and deeper hole will do the job quicker, but it seems to me that even a .22 does the job in the majority of cases. I think we overestimate the commitment of most bad guys. The vast majority of them are opportunists. They are looking for an easy target, and are not looking for a fight.
Now I'm not saying we should all retire our .45s, .357s, and 9mms. If I hear a bump in the night I'll still reach for my .357 or my 12 gauge. But I don't think we should just dismiss the .22 as ineffective, because there are a lot of real-life cases where it has been effective. There are a lot of reasons why a person might use a .22 for self-defense, and in some cases it might be the best choice.
I'm sure I'll get a lot of the same cliches we always hear when the topic of caliber is discussed. Yes, I know, bigger is better.