While I have no quarrel with using a 20ga for deer and think its very appropiate tool for deer killing under 100 yards, I for the life of me can't understand how someone can make the statement that it will do it as well as a 12ga with all else being equal. How can a smaller diameter projectile with less energy at impact work the same as a larger diameter, heavier projectile? I kill with both, just boggles my mind when I hear guys say "switch to a 20ga".