I’ve taken 100 pound white tails with my 223 (in Montana - you can hunt with anything). I wouldn’t use it for anything bigger, but then again if I’m in a survival situation by myself, I’d rather not shoot anything big!
And the 223 won’t pulverize a rabbit or coyote...;) I’ve seen what them speedy 270s do to small game! Shoot a rabbit or coyote or beaver with a 223 and you still have a lot of good meat.
One thing about the .270, a good clean shot to the neck will break it. Don’t have to worry about looking for the deer.
I shot an Axis doe last year (ummm, ummm, good) and flipped her completely upside down while her head was still rightside up. Never knew wwhat hit her.
If necessary, I can shoot the letters off the paper target at 50 yards with my Savage .22. A young deer’s head would be easy pickins.