RE: you're going moose hunting
I would decline the uncle's offer to buying a rifle for me. I would probably offer to buy him his choice of rifle just for the fact that he's offering me a moose hunt. I have several rifles in my stable that work work without a doubtbut the one that would go with me is a Sako M75 SS in 375 H&H topped off with a Zeiss 3x12x56.
As far as bears goes I would bring a couple of cans of pepper spray and either the 454 Casull or 480 Ruger in a Super Redhawk.