SC, I think I understand your questions, but what you have to realize is that other than Adrenalin, a deer (other animals too) have built-in instincts! Some deer that I have tracked, you would just wonder how they kept going! A human would probably given up and died long before a deer will!

Most deer that "drop" are hit in the spine, brain, or double shoulder. Very-well hit heart/lung shots are DOA, but they usually are going on a "death-run," 10 yards, to well over a 100 yards. Think about it, how far can a dead deer run in 2 or 3 seconds!