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.
"The ultimate authority ... resides in the people alone. ... The advantage of being armed, which the Americans possess over the people of almost every other nation ... forms a barrier against the enterprises of ambition."
- James Madison