I used to have a .444.....got a sizing die only and used my .44Spl. dies for the rest. I only had to resize when the cases wouldnt chamber up cleanly any more. I think I even used the carbide .44Spl on the .444 brass on occasion. I have messed about with a bunch of calibers, and often kept my die sets, so I mix & match to do up 'oddballs' that come my way. I have thought it better to find if a gun would shoot before putting a lot of money into tooling. FWIW, the Lee die sets are so reasonably priced that, if a gun is working out, you should just buy the right set. (and no, I dont work for Lee)