I regularly load my .416 Rigby on my Dillon AT500. Same as a 550B, but I don't use an automatic powder measure, although I do use automatic primer feed. The only problem you will have is you will probably need to have a current shell plate machined to accept the .470. Also you might want to get a set of Dillon lock rings to use on your dies as they are smaller diameter and don't rub against one another when you are putting the dies in the die holder.
You can send a PM to me if you want any further detail on how I did anything. Hope this helps a bit.