When I was about 16, I took the Stevens Semi-Auto .22 rifle hunting during the winter. A buddy and I walked down the long camp road and I saw a white hare about 25 yards away, sitting motionless, but headed toward the right. I shot it through the lungs, but it didn't fall over, so I shot it again. Same result.
I emptied the gun on the rabbit and apparently hit nearly the same place, because I could see right through the critter! It was dead, but apparently didn't know it. I reloaded and shot it through the head and it finally fell over.
Never shot a group on a critter before or since. LOL