If you think about it, the weight of the 2 balls is no more than some of the heavy conicals used today with the same charges. As long as there is no space between the two what could happen. If your rifle is safe to fire heavy conicals then why not a double ball charge. Would be like some of these new pistol cartridges that fire multi balls in .38 special, 9mm, and some more popular pistol rounds.. I know these are in brass cases but they also shoot higher pressure smokeless powder and they are safe. Im just using this as a comparison. Some of the muzzleloaders today are made with rifle grade steels that could probably take even more pressures than they are reccomended for. The companies have to have a safety margin built in when they put reccomended loads with their rifles just as saami does in their standards for smokeless cartridges. Can someone explain why 2 balls could not be loaded safely based on this.