ETA:
Whatever you call Loughner's weapon or how you phrase its capacity, Loughner's weapon allowed him to shoot off 30 - no, 31 - bullets without reloading, and when he paused to reload he was immediately taken down by unarmed people in the crowd.   The point is that had his weapon not had the capacity to shoot so many bullets without reloading, fewer people would have been shot.

Yes, the kind of weapon does make a difference.