22 LR For small critters like Rabbits, squirrels, Game birds
243 For deers, predators
300 WSM, good on powder usage, and if I have to save myself to eat, shots would be with in reason as not to burn unnecessary calories or energy, so 800 yards would be my limit to walk and retrieve. This caliber would kill anything with in that yardage.
That question is loaded! Hunting in my state any thing over 25/06 or there abouts is over kill,Hunting the world now thats a big question , 50BMG 30caliber something and a meat gun down around .243 make em all <1" and I am happy!!gun)
6X47 for prairie dogs and coyotes at short to medium
7mm-08 for deer and antelope at short to medium
300 win mag for everything at long range
22LR the most practical of all...practic...practice...practice