More and more camps around here are adding paintball to their list of activities. I believe that is is ok only if the scouts are shooting targets and of course have adults that are trained, NCS Shooting Sports Director for example.
Though it is only at targets it does add another level to shooting sports for the BSA. BBs, .22s, shotguns, slingshots, paintball, and marshmallow guns. In some cases I believe black powder is allowed, I have been told it can only be demonstrated though.