Wow - Bigger differences than I would have guessed on that 45-70!
I have only ran into reloading problems once and that was with the 8mm Mauser (8x57) having significant differences in case capacity. Seems the biggest difference was between the American and the European manufacturers, with some European cases holding as much as 1.5 more grains of powder. Made me wonder if the American manufs purposely reduced the case capacity to better download their "8mm Safe" ammo? If true, this spilled over into the Rem and Win new cases they sell in bulk.