Lee makes a 400 grain mold with two crimp grooves. Coincidentally, when seated out in the lower crimp groove, case capacity is the same as the .475 Linebaugh.
I'm not telling YOU to do this, but I have used the same load in my .480 as in my .475 when using this bullet. There isn't much room left at the end of the cylinder, but it does fit and the revolver will take the standard SAAMI pressure of the .475 Linebaugh, as they aren't that far apart; 48,000 for the .480 and 50,000 for the .475.
My first .480 was early enough that the first box of ammo I bought was head stamped .475 Ruger. I've never seen any others.