Certainly not a 12" vital zone but a 12" body profile from shoulder to brisket on a big dog is about right. That one was a BIG one. Naturally the vitals are much smaller than that and hitting the fur outside of them will result in a wounded animal.
Knowing the relative body size of the animal, my rig's zero & bullet trajectory is what killed that dog. Or maybe I just got lucky...
I should reiterate that a 300yd shot where I hunt is a rarity , hence my 200yd zero.
