Posted on another forum earlier this year:
Had some polar bear funtime in Greenland in April. Before we left, our logistics guys were talking us through the pepper spray, the 4 types of marine flares, the rape alarm perimeter (bearimeter) fence and the .308 rifle with the hollow point rounds, saying "you won't need any of this, though. You'd be very unlucky to see a bear, chances are less than one percent."
4 days in, I looked out of the tent door, Bear about 100 yards from the tent, coming straight for us. Couple of pen flares did nothing to faze Mr Bear, he just kept coming. Next up was the pistol flare, had no clue how far it would go, but guessed right and it landed right by him. He broke away from us into a run for 10 seconds, then slowed to an amble, looking back at us. Couple of rifle rounds over his head and he hurried off down the valley.
Then he just lolled about in the sunshine for ages, rolling in the snow, about a kilometer away. Seemed he knew the range of everything we were firing at him! Then he started back up towards us, more boomstick, off again, more lolling, back towards us again, more boomstick.
This was over the course of a few hours, and it was a beautiful day with great snow. We wanted to get up something, but we didn't want to get up and watch Mr Bear tear our tents up, looking for the tins of mackerel fillets in hot chilli oil (they had pull rings, he'd have been straight in with a deft flick of a claw!)
We got kitted up for touring, each of us packing heat of some sort, and started moving towards him, couple more rounds when we were a bit closer, then waited and watched while he headed off up to a col. We skinned up to where we could see his tracks to see if he was good and gone, and he was. We had a good run down the newly named "Bear Face", and had a slightly less good night's sleep that night!
When we got back to the airstrip at the end of the trip, the guys said "You were so lucky to see a bear, chances are less than 2 percent!" We were the second group in 20 years and 170 expeditions they'd done the logistics for who'd encountered a bear, so we'd just doubled the stats!
Back to STW: given the guidelines for shooting to kill a polar bear: ie: wait until they are 6-10 feet away (bolt action rifles, so if you miss, you might not get another shot), I might stick to the flares and the rifle. I was never that keen on the idea of the pepper spray!