could be just the moment of drawing on a deer is more tense than target practice. Unfortunately you can't target practice on the real situation. Muscles tense up and weird things happen. Try target practicing with your buddies for some $$$$. Add a little something extra going through the brain!! It's the same old phenomenon as in golf. sit there and rip one after the other on the range, but play in front of a gallery and ......WOW!!! what happened??