Like most here, I've seen them vary from falling over to zero reaction upon a killing shot. I hit a walking cow at 50 yards who didn't flinch or anything. A friend watching the whole thing watched her fall over dead about 12 steps after the shot.
Usually, a lung hit will cause them to hunch up, like a guy getting punched in the gut. I keep shooting until they wobble or fall over completely. I've never seen one wobble and not die shortly thereafter. I have seen them get knocked over by a shot, then get up and walk off. If they're in thick oak brush or somewhere I'd have a hard time tracking, I usually go for the high shoulder shot. Everywhere else, I go for the lungs.
Go. Odds are excellent that you'll have a blast even if you don't fill your tag.
