Hmm well back to the original question about minimum caliber for Grizzly.
Gee I just don't know that I would want to flirt with the Minimum on a animal that could turn ME into the one being hunted. I think I would opt for something in the mid to higher range to hunt the beast when my life has a chance at being at stake.Especially if I am inexperienced enough to have to ask the question to a bunch of folks on the internet.
It seems to me to error on the side of too big than just the minimum.
Just my opinion