Since the "new" 450 marlin rifle and round are the same except for the belt on the cartridge, this means I can handload the 45/70 in my modern Marlin 1895 to the same pressure level as the .450 right? After all you have the same case capacity and the same rifle. I've got some reloads for a Ruger #3 that come real close to a .458 Magnum. I bet the Marlin could handle them with no problem. Input sought. I still have my 30 year old Hornady reloading manual.