I have found these sources useful for choosing ammunition for home defense: The first is a youtube video entitled "Testing Five Different .22 Bullets". The second is tactical brief #10 at the firearms tactical institute website firearmstactical dot com, entitled "Shotgun Home Defense Ammunition". What these did for me was to get me thinking about optimizing ammunition for the goals I want to achieve. In a self defense situation, I assume many would want to minimize collateral damage while effectively stopping an attacker.