Old Ugly, your .338 is about as good as any rifle short of an African "stopper", assuming you get a chance for one or more good shots. The only guy I knew in Idaho to kill a bear in self defense shot a black bear that wouldn't leave camp with a .308. As I'm sure you know, that's a lot different than a grizzly surprised while napping or defending a kill or cubs. It's not an experience I've had, and not one I'd like to have. Bear spray does not depend on precise aim, and it uses the bear's sensitive nose against him. Of course there's that story about differentiating grizzly doo doo from black bear by the little bells and peppery smell. A good head shot with your rifle or a heavy revolver may stop him, but anything else is likely to kill him not quite soon enough. But hey, that country would be overrun with tourists if not for the bears. Enjoy 'em.