To relate a story... Years ago, my uncle was telling me about a young man sitting on a stockyard farm gate when he was struck in the forehead with an errant .22 bullet and knocked unconscious... This happened in Howard County Missouri in the mid 1950s...
In the late 1990's, I was in the lounge at the Holiday Inn in West St Louis attending the Buick owner's car rally and happened to be sitting next to a guy and we were talking about home town areas and he mentioned that he was from Howard County, next to my home county and we were exchanging names of common family knowledge and he mentioned that he had been shot there many years ago and had known my uncle... One thing led to another and he was the one sitting on the farm gate...Still carrying the bullet as it had been too dangerous to remove at that time...
It was determined that the shot had been fired from a farm located approximately a half mile away and had been totally accidental....
So, as far as range, that is a pretty good answer, but as far as being effective, I'd have to say it leaves something to be desired past normal shooting distances...