The Dali Lama on self-defense

But if someone has a gun and is trying to kill you, he said, it would
be reasonable to shoot back with your own gun. Not at the head, where a
fatal wound might result. But at some other body part, such as a leg.

Well, I'd say he's on the right track. Now, if you're willing to shoot at someone (no matter what you're aiming at), you're saying that you're willing to risk killing him to keep him from killing you. There is no such thing as a guaranteed incapacitating, but non-lethal gunshot.

So, if you're okay with that, then you might as well play the better odds and shoot for center mass. And if you want to be effective, you'd better practice. And for any of it to matter, you have to be "allowed" to carry a gun for self-defense.