Having lived in Fairbanks, Alaska for a few years, traveled the bush,and hunted grizzly once, here's my take on the issue. First, this is my opinion based on reading, talking with bear biologists in Alaska, and my personal encounters with black and grizzly bears. Blacks are the bears most likely to hunt people as food. Grizzly's attack then leave you alone (although you may need a hundred stitches or so). I personally carried a .338 with me until I got my 12ga pump. There are many more nonviolent encounters with grizzly bears than there are violent ones. Pepper spray has worked for people who used it before the charge - send a blast down-wind to the bear. I cannot vouch for it's effectiveness during a charge. I know people who go out in the bush without spray or a firearm and have no troubles, just being bear aware. If you are going to shoot a grizzly, aim for it's shoulders. Take out it's ability to run and then finish it off. I got invited to hunt with two guys I knew but had never hunted with before. We were supposed to be big MANLY hunters. We all had .338's (one KDF, my ears permanently ring to this day!). This was my bear, maybe 50 yds away and when I shot he dipped his head preventing my chest shot from getting him, bad shot (blasted his lower jaw btw). After my shot, the bear swung around and ran for the other side of the glacial stream and up a ten foot embankment. The other guys meanwhile, showed their military training, peppering that bear with bullets. All told, the bear had six .338 wounds, these slowed it down. My follow up shot put him down for good. When a bear is excited nothing will keep it from reaching you unless you can take it's front legs out immediately, imho. I recommend a 12ga. with slugs or buckshot. One more thing, don't read any scary-bear tale books right before your trip, most of the time your imagination will ruin a trip before any bear will.