RE: #age for mechanical broadheads
Depends on the head you choose, your draw length and how efficient your bow is. Some mechanical heads actually penetrate pretty well, others not so much. I personally have a short draw length with a fairly low poundage (55-60) and I shoot two blade Nail Drivers. They work just as well as Thunder Heads for me. I do shoot a fairly efficient bow with heavy arrows though which probably doesn't hurt.
Paul