He's not just some regular guy who bought a gun and went mad though, there is some preparation in where he finds his targets. He made the wise descion not to use a building.

But i agree he isnt a golden bullet winner or anything just a guy who watched deer hunter 1 too many times. But he has been out and got a good aim, but i would have had been kind and shot them through the medula so at least then they wouldn't feel it.