Um. Dead animal = bullet that did not fail. By definition.
Well that's the stupidest thing I've seen all week
Nearly every wounded animal ends up a dead animal EVENTUALLY. That doesn't mean an adequately deep and wide wound was delivered to ensure a humane and timely kill with the animal near the location it was shot and a sizable blood trail to follow if it moves..
A bullet success is a bullet that a) expands and b) has the capability to penetrate the thickness of the animal and exit, including breaking skeletal bones if need be, on a side or quartering shot.
It's entirely possible to have an animal drop quickly from a total bullet failure IF you get lucky. Is you plan to count on luck?