I have killed a bear with a mechanical head.Rocket steelhead 11/8 diameter.I got a complete pass through on a 225 pound bear.I wasn't hunting bear specifically at that time.If I were to be hunting in a baited bear situation where the shots are likely to be 10 to 15 yard shots at a bear that is fairly preoccupied I would opt for a fixed blade head,likely a magnus stinger or one of the other fixed blades that have a reputation for penetration,accuracy and toughness and of course fly well out of my set up.