Not actually seen, but heard hear-say. I think most failures that I have heard about usually involve high-powered rifles at very short shot distance. I recall one guy told me his bullet (325 WSM) passed right thru a doe at 13 yards. Duh! That bullet was moving so fast, never had a chance to expand and do any internal damage, and left with almost as much KE as it entered with. I've never been able to convince the hyper-magnum nuts that a bullet that passes thru does not deposit ALL of its energy into the animal since it is still leaving at a high rate of speed. Wrong tool for the job.
NRA Life member
NAHC Life member