I am certain this man is an incredibly skilled sniper. But how do you measure this skill? For this you will certainly have  to go to a gun range.  In real life there a just to many variables  in place.  At that distance a little gust of wind, the target moving at he wrong time are one of many. You could shoot another  100 times and not repeat the feat.  A lucky shot seem to be the more appropriate description when it comes to those super long distance shots  hitting the intended  target.