I shot nothing but LARGE groups when shooting XLC's. In my opinion, they are the worst bullets Barnes ever made. Your milage may vary and a few guys seem to love them.
For what its worth, the TSX bullets are the easiest bullets to get to shoot well. I shoot them bare without any trouble but my buddy sprays them with moly (spray & bake) and they shoot very well and foul very little. Not bad for solid copper bullets.