I grew up using .22lr single shot to kill hogs on up to 300lbs and larger. It's all about shot placement. Of course these were hogs that were being held by good catch dogs and shot in the brain but .223 is plenty of gun for hog hunting if you have a clue what you are doing. 300 Win Mag is not enough if you don't.
As for deer, my brother in law killed two last year with his AR in .223 with 55gr Vmax varmint loads and both didn't run far enough to have a problem finding them. Would have been rough if you had to blood trail them since there was no exit wound but shot placement is always more important than caliber.
My uncle in Alaska used to shoot Caribou with a .22lr pistol and never had a problem taking one down by shooting it right in the ear and this was running alongside it on a snow machine.
Last edited by slappy; March 21, 2013 at 09:41 AM.