So here's what i'm gonna say, you have to be able to hit the spine. PERIOD. You WILL NOT get both lungs, ever. Don't aim trying to hit the vitals on the money, cuz you won't get 'em. You have to hit the spine and go through the heart, that's your best choice. Remember a heart shot takes away the pumping mechanism, so the deer won't pump as much blood as you would expect. You have to know what you're comfortable with. I've taken numerous deer direclty underneath me with a spine kill. But only because I know I can hit the spine, and where the heart is.