Just wilderness survival? .22 rifle, hands down. Small game is what will feed you and there is little waste. Robins are as tasty as a Dove. Or so I have heard.
Don't know if robin is as tasty as dove but I can tell you that kangaroo rat tastes like filet mignon after a couple of weeks of desert survival training.
Oh and go with the .22. I knew a lot of old timers when I was a boy that killed deer with a .22. Made fun of me for using something bigger. Old country gentlemen that cared little for game laws and more about putting meat on the table.