one thing that I have found is that if you have to stop the deer they are already on alert listening to every sound with full attention. If you don't to stop them wait until the stop on their own. That way they have no idea whats going on when they hear the bow. That is when a fast bow comes in handy. I had to stop a buck two years ago to make a shot. He was roughly 30 yards and my bow shoots 322fps with a hunting arrow. He ducked the arrow without even trying. Luckly I didn't range him and guessed him at 25. He dropped right into the arrow! better lucky than good!