It is recomended you use a 50# or greater Bow on big game here in Alaska. I don't think I would try anything less than 70 # unless I was sure of my shot and I was sure the bear didn't know I was there. It only takes a brown bear a very few seconds to cross bow range. At a full charge he will most likely at least hit you before he will drop from a well placed second shot. This part of the lure to hunt a Brownie or a grizzley with a bow. Search for links under "bow hunt brown bear", or go to.
YouTube - brown bear 08 alaska YouTube - Brown Bear Bow Hunt
But who is doing the hunting?
Hunt TV