My goal, every time I shoot, is to make a humane kill. I can't stand to see animals suffer. When I want to drop a deer instantly with a rifle, I'll wait for a clean shot and aim for the shoulder blade. The bullet striking the shoulder blade seems to transmit energy to the chest cavity and will stop the heart on impact. The deer drops like a sack of potatoes. If you hit a little high, you take out the spine and the effect is the same. However shot through the chest taking out the lungs or heart will generally only allow the deer to live for 5 or 10 seconds. However far they run in that time, is the distance you have to track them.