Okay, I am confused on the Crit chart. Are you supposed to use the number on the d20 that you rolled for the To-Hit?
If that is correct, then you will almost always be hitting them in neck or the head. I don't know about anyone elses game, but I do not like the idea of my players have improved the crit range much beyond 18 (if that) because it makes the game very imbalanced.
Maybe we should have the player roll a separate d20 to find out where it hits?