Inside of fifty yards if Bambi has no idea I am there quite often I will run a bullet through just underneath the skull. No mess no fuss and no chasing them down. Beyond that I like to watch for a quartering angle where the bullet will travel just over or maybe through the heart but not touch the shoulders. If it's a deer I want and it doesn't give me that quartering shot I like just behind the shoulders. With the crossbow, double lung behind the shoulder or if facing me straight on and does not know I am there, in just above the sternum and out near the umbilicus. I shoot exclusively for my table and will not waste meat, but for rare occasions when I have to put then down right now when I will use a high shoulder shot at somewhere past 200 yards.