I've never been a sniper in the military but maybe it has to do with the different protocol Canadian snipers have before attempting a shot that long. Perhaps us military snipers prefer to take shots that they know they have a higher probability of hitting and the Canadians just lob bullets at 2+ miles??? idk? just kidding.. but I would bet the number of shots taken at those ranges by the Canadians is greater than the number taken by US snipers.