I'm a total novice to shotguns and rifles. I believe my next purchase will be a shotgun. I was wondering if I were to take a shotgun into the wilderness while camping, could I reliably take out a bear with a 12 gauge shotgun? If so, what shot should I use? I was thinking a heavy slug... What's all this talk about choke. What is it? Lastly, is the recoil between a 12 and 20 gauge a huge difference?