458 sizing will work just fine. You mentioned that you are looking at a size of 457 and three tents. I don't know anybody they can make that die either get 457 or 458. I do not know if you know how those are machine but it is a Finnish rammer and it would have to be an adjustable. Raymer in order to get the three tents the other problem with that is that is made out of an incredibly hard material and the only thing that will cut it would be a die reamer or die drill my two cents

Slim 400