The latest fad regarding defensive pistol calibers seems to be the claim that they are really all very much alike and, therefore, it doesn't matter what you choose to carry for your personal defense. Your Honor, may the record reflect that I respectfully disagree.
The purpose of a firearm for the defensive shooter is to stop the attack. Any handgun cartridge is capable of killing a human attacker, but killing is not the goal; stopping the attack is what we are after. And the vicious assault must be stopped right now. Since all handgun ammunition is really marginal when it comes to stopping, we need to deliver the biggest, fastest bullet that we can handle. This is what will do the most damage to the vital zone of the attacker and cause the stop.
Now I grew up reading Elmer Keith and, of course, became a great fan of the .44 Mag. And I still like it—as a hunting round. Unfortunately, I found out that I was not as tough as Elmer Keith. Simply put, I couldn't manage the full-house .44 Mag round for quick double-action shooting. And, therein, lies the rub. For defensive purposes, we need to be shooting the most powerful handgun round that we can handle accurately and quickly.
We are fortunate, today, that our ammunition manufacturers have given us defensive bullets that will penetrate properly and still expand properly. Given that fact, the bigger bullet will cover more area and has a better chance of impacting important tissue within the vital zone of the attacker. Therefore, it has a better chance of stopping the assault. Bullet weight, expanded size, and penetration depth, all play an equally important part in stopping the action.
If the .380 is all that you can handle in a fast, accurate fashion, so be it. But don't fool yourself into thinking you have a world-class fight stopper. You really don't want to have to get into a life-threatening experience to find out how wrong you are.