This is always a tough question.
For all around use in a foraging situation, I would choose an M6 Scout. The ugly duckling of Air Force and Navy survival kits. I actually have used my M6 for rabbit, squirrel, and dove. Enough to keep me fed for the 5 days that I decided to challenge myself.
For two legged game, I would go with the AK. If I had my choice, I would take a Siaga 20" barrel in 7.62x39. Try one with Wolf Ammo at 300 meters. See if you can't put 30 rounds into a torso sized target with iron sights. It's not a battle rifle, but that can be fixed. Just search around here on GUNCO for guidance.
For home defense, 12 Ga. Remington 870 or Mossberg 500. Any model. Own a hacksaw, and a copy of "Red Dawn".....Now seriously; I get asked this question all of the time. People ask about handguns, EBR's, etc. "My friend told me this", or "my brother-in -law told me that". Simple question back is "How often will you practice?". If I get a blank look or a stupid answer, my response is: "12 Ga., Remington 870 or Mossberg 500. If you run out of ammo, it makes an effective club".
End of conversation.