It started becoming pretty clear by the end that the producers where trying to manufacture a specific winner. Some of the elimination challenges where blatantly in one of the competitors favor, to the point of being unfair for the other. Granted, the show supposedly promotes the most versatile shooter, but what are the odds of having your pet firearm drop into your lap at the challenge as the other guy stands there looking confused? He still appears to have a chance to the lay TV viewer, but its for appearances sake only.
The producers wanted Jay to win against his opponent to drag out the whole 'military vs. civilian' shtick they had going for a while, so they set up the .22s to favor an olympic style target shooter (like Jay). Next they wanted Jamie to win against Jay, so they gave him a rifle they knew from his application he was very familiar with (not to mention more capable with, since the M1 is a beast and Jay is an itty bitty ol guy). Then finally, they wanted Chris to win against Jamie, so they gave him a shotgun and clay targets to play to his most publicized strength. This whole thing is right out of the Hulk Hogan playbook.
In the end, the other three had very little to do with it. The producers wanted Chris to win because he was the least likely to cast the show in a bad light down the road. Facts are, after Richard Hatch from survivor pulled his little tax stunt, the show took a huge hit in the ratings. Chris has a wife and kids, so is the least likely to pull a crazy stunt and cost the show viewers and, as a direct result, advertising $$$. Him winning is in the best interest of History channel, the show, and its producers.