Wow. I opened a can of worms here. For what its worth, my buddy is in the FBI on special teams and when I asked him this question, he told me a .357 has enough power/force (velocity x weight) for black bears, but maybe not Grizzly depending on size.
My own thought was to keep it in the truck (covered out of sight) because that is far more airtight than the camper and less likely to "leak" smells. Of course, I will be sleeping right over the cab- what 12" from the top of the door? I keep a .357 in the camper and also bear pepper spray. I figure it this way: if I am in the camper and bear wanders over, I will see/hear it. I should have plenty of time to 1st set off the car alarm which ought to scare him away. My dog would be barking up a storm by now too. If not, I've got pepper spray and finally the .357. In a tent, your ability to not be surprised and react rationally is far, far less.
You can't really hang or bear can cold/frozen foods. When hiking, I guess you have to store the cooler somewhere- truck or camper. My preference would be camper (less expensive to fix if "can opened"?).
We end up brushing our teeth, what, 50ft from the campsite? So, our smells are out there.
Of course, maybe I'll just stick to pasta in bear country which should be relatively safe, but boring.