my cousin killed a full grown black bear on her front porch using a .22 rifle a few years ago.

Somewhat related anecdote: when I was a teen, a Greyhound bus hit a big black bear one evening just down the highway from my parent's home. It was still alive, so a neighbour got his hunting rifle and put it out of it's misery. Apparently the RCMP got wind of it, and at 11 o'clock the next morning a patrol car pulled up to the spot where the bear, now very visibly bloated, lay in the ditch. A nervous young officer took a .22 rifle out of the trunk on proceeded to "kill" the bear with several shots.