I can send you a .357 Max case, but seldom will it chamber as is. Some folks have taken only 0.10" out of their chambers to ream the Mag to Max. May I suggest you try some 360 Dan Wesson brass. It should chamber just fine and is a little bit longer than the Magnum. I can only find one piece of the DW brass, you can have it if you want, PM me your address, if so.
Thanks, Dinny