There is a reason bush pilots carry .22s. They can be used to take a lot of game..
If you have a .30 with 100 rounds and .22 with six boxes of 500(thats 3000 rounds) you can take more then enought game to feed your self. You would only need the .30 if you had to deal with a bear or some thing. Shooting a large game animal in warm weather mean that most of it will go to waste, or you will have to spend time preparing it to save the meat for later. Even in cool or cold weather the meat may cost you more then it's worth and can attract things you don't want to meet.
In fact a .22 is perfect for shooting ducks, geese, rabbit etc because there is not a loud report and you may be able to get two or three before the rest get wise to you. This is talking about a lost/crashed in the woods situation.