The 470 and 500 will always be more available and will do anything the other caliber will offer with less bother as far as finding fodder.

One point on the new Hornady loads, I understand they may not duplicate the original loading and may require some regulation in older guns. I know that the company has not released the product yet, but advance batches are on their way to some companies in Europe, particularly Heym so they can test and regulate the new production doubles in this chambering. Dave