Hi Chancesr and welcome to TFF. Although my search lead me to this place, no one else had dies for the 7x57R as you stated. Here is a link that not olny has loaded ammo, but dies and brass too. Looks like you are in luck!
Old Western Scrounger
Good luck and keep posting. We are glad to have you with us! In the search window type in 7x57r. Away ya go!