They work well on small game like rabbit and tree rats, but I would not trust the penetration for self defense. Once I shot a buck with a rifle. When I got to him, he was down, but still alive. I decided to shoot him in the base of the skull with the waddcutter load you are talking about. It went in, maybe half an inch. Then he really started kicking.. When I later skinned him, I was able to pull the bullet out of the bone with a pair of pliers. Stick to full power hard cast semi-waddcutter hollow points (the old FBI load), or light weight hollow points at plus P velocities to get the most stopping power out of the 38spl.