the largest case I have reloaded much for is the .375 H&H and cases last as long as any other case.....and it depends whether I use a scale for powder or a scoop shovel...

I use a wilson case trimmer and trim them about .015 under the book recommended and try to keep the lengths fairly uniform because I like to crimp these big guys. They don't have to be crimped BTW.

Actually these cases are no different than cases for a .270 or a .22-250.....I trim them about every third shot.

Cases such as the really big ones used in double rifles may in fact be very different being normally straight walled and normally lower pressures.

I hope someone post info about this class of cartridge......excellent question.