RE: 30 cal carbine
Fisrt of all, you never "just blast away" at any game animal! That's just plain irresponsible in my opinion. Second of all, always aim for heart/lung area. I myself have only used a headshot once on a deer, and that was from about 5 yards to finish him off. You'll never hear (or see) me recommend a head shot, even to expert shots.
Cory