I almost never in PA carry a sidearm, unless I'm on private land, and then it is generally a 45 LC revolver loaded with snakeshot x3 and two slugs. If I get into more trouble than that?
Well. I generally don't shoot the bears, I AVOID the bears by practicing good camping policies. Two legged crits, that's enough, unless I run into local militia on ops, or heavily armed weed farmers, both dangers I admit.
I like a .410 as I know how to shoot it, and the ammo is interchangable to a degree with 45 LC
Now the ultimate survival gun is one of those black rifles I see in the movies, 'cause I wouldn't have to carry any ammo! They fire forever, and hit anything you point them at, except a main character of course.
Realistically, even if I didn't have a pistol, which is probable, for weight I'd like a .22 rifle. And lots of ammo. I'd take the fact I can't shoot bears for the convenience of shooting a ton of small game.