I think that the grinders that do bones well (and are well built to last) are extremely expensive (like thousands of dollars), and are professional grade. You may find something cheaper that may do chicken bones in a limited quantity though.
Not that I know anything about bear meat, but I would cut it with something leaner because of the fat. But wow, what an opportunity for a diffferent protein source!
I agree with the above. Grinders that will grind bones are lots of money. I'm trying to find a little grinder just to grind tripe and even those are a good chunk of change. If you really want it ground you can ask a local butcher to do it for you and just pay by the load or something.
Thanks I would love to feed them whole bones but unfortunately because of Coopers Megaesophagus he has to eat standing up and must stay in that position for 15 - 30 minutes after eating. The food will not go down his esophogus if his head is down or if he is laying down. Although I am happy that I tried raw, it is the only food he hasn't regurgitated in two 1/2 years!!