My thoughts as well. Animals have been killed with non jacketed, lead alloy bullets for hundreds of years. Bullets that by today's standards were quite soft and expanded even at relatively low velocities. If the copper or gilding metal skin becomes separated from the dense lead core within the animal, it's behaving like a sabot round from a tank. The outer shell/sabot stays behind, while the dense core punches the hole. What's this about chest hair?