I can't imagine anyone walking through a load of copper plated #4 shot at close range even from a 410 and in all actuality any shots made in self defense most likely will be at very close range or someone will have a lot of explaining to do to the police. I have seen the demo of it on TV where the guy fires 2 rounds at a plywood perp from the the driver's seat of a vehivle outthrough the open passenger window and it put a couple of pretty impressive holes through the plywood perp. I don't think human skin and tissue is a tough as plywood. While on the Fire Dept I had to do 4 years on the ambulance andI had the opportunity to see what a 410 does to a human body fired at very close range and it is ugly.