I go with the Browning 81' BLR take down in 450 Marlin as my bush plane bear defence/survival gun.
The 350 grain jacketed FP bullet carrying 3500 ft-lbs in muzzle energy will send any North American animal backside over tea kettle and it won't get back up.
It has a really effective Pachmayr recoil pad on it, is box fed and has no lawyer safety junk to screw up at the moment of truth when your life is on the line.
(Murphy's Law: whatever can go wrong WILL go wrong and at the worst possible time)
It still kicks but I figure a sore shoulder is better than a missing shoulder that has been torn away by the jaws of an angry brown bear.