I've seen quite a lot of deer killed with quite a variety of weapons, bullets and broadheads. I've also talked to guys who have seen a lot more. Most importantly, guys with dogs that track wounded animals. They tell me all kinds of stories about "perfect shots" and "bullet failures", that turned out to be gut-shot, leg-shot, something other than vital zone shot, animals. Interestingly, I have yet to hear a single story from such a dog tracker, wherein the animal was hit in the vitals and the bullet or broadhead failed to perform.
PerZacklee! Thanks, Peetza!