Yes, i've seen hogs still move, and everythign after a shot to the middle of the head, somtimes the bullet breaks up or somthing normally a second shot does it, never seen third one used but i heard about it. If it works its very quick, cause if you got to skin so many hogs in a day you don't got time to be sitting around playing doll with a dead hog. I've killed chickens too, we just use an axe
The way KFC does it seems much easier, and faster.