45 ACP. Is it the weight or the diameter?

I have tried unsuccessfully to research this and frankly, I give up. Perhaps I should stop thinking about this. I’m really fond of the .45 acp. I generally carry one for self defense in various configurations. My wife says I accessorize.

There are of course different weights of projectiles from 185 to 230 grains. In that respect which is best for stopping a threat? The lighter grains feel like they recoil less, but is it the heavier bullet that does the trick or the diameter that causes the larger permanent wound channel?

I absolutely believe that accuracy is the best way to stop an attack and that caliber is probably not relevant. So is bullet weight relevant?