I've found with bow, lung shots tend to put them down quicker than anything. Pop both lungs and they struggle to breathe, panic, and tend to kind of circle rather than just balls out straight run. Like Hatchie said though, no deer is predictable. Double lung pass throughs give you a LOT better blood trail than a heart shot. Not heart, no blood pumping out. Both lungs, they spray blood with every attempt to breathe.