Man, no way would I purposely shoot at the heart. Some people do, but not me. Why should I when I have a target that is over three times the size that will drop a deer quicker then the heart. Plus, I want my arrow to hit exactly where I aim. Not say, well, I' ll shot here, and if the deer moves does this, then I think I' ll hit here, or if it doesn' t do that, it should hit there. Thats why I will only shoot at relaxed deer, and keep my bow as quiet as possible. Nothing is 100%, but it sure helps the chances.