I think I would go with a .30-30 lever action rifle, and a .22LR revolver. The .458 SOCOM AR15 would be a strong contender, but I have no experience with its reliability so for what I know it would be the .30-30. I would go with Barnes copper bullet ammo.
If I have a short, handy rifle for defense and hunting then I see know need to carry a 4lb handgun and a few huge cartridges too. I would rather have a lightweight .22LR revolver with a brick of ammo. Or a G26 9mm, several loaded mags, and a .22LR conversion slide with a brick of ammo!
If weight was not a factor, that is staying in a fixed area with occasional forays, then the M1A .308 and 180gr premium ammo would be my choice. But if I have to bust brush and hump ridges for many and many a mile, then a lightweight and slim carbine like the Marlin or Winchester gets my vote. If not .30-30 then lever action in .44 Mag or .45-70 though that is getting to much larger and heavier ammo.