My weapon of choice for deer/bear sized game is an 8 inch Frying Pan, teflon coated and with a solid base. I've tried 10 and 12 inch, but the velocities are too low and I get better accuracy from an 8 inch. Here is a picture of me last deer season sneaking up on a deer with my custom 8 inch Frying Pan:
Just don't use aluminum (it's too light) and make sure you give the bear a good whack.