Your another one who thinks all attacks come with a warning! Well my friend your wrong.
I don't see where you're gotten that. All bear attacks come from bears. Once again, the OP was talking about deer/elk hunting, so we aren't talking about crawling through stuff where you can only see for feet. I do know that it is possible to sense a bear before he's chewing on me, and I do know that the best thing I can do, regardless of gun, cartridge, bullet, or lack thereof, is to be AWARE OF MY SURROUNDINGS, and if bears are a concern, I should probably not put myself in situations where I'd be at quite a disadvantage. If I haven't done these things, and then rely on a firearm to save my ass, then I get what I deserve.
