Just one last thing I'd like to qualify - once headspacing is sorted out, then the 15+ case life means that incipent head separations are no longer an issue and the cases will die of a cracked neck instead. You could anneal the necks before this happens and extent the life even further but I've never done this since most of the cases I reload are easily obtainable and not too expensive. Some manuals recommend against annealing because the rest of the case is still being work hardened and could crack out of fatigue(?). (But then again, I'm not sure this type of failure would be all that catastophic, a bit like head separation I guess. The worst failure I've seen was a pierced primer but no one was hurt and firearm "damage" was reversible on the spot - a magazine floor plate blew out.)

My 375H&H and 458WM cases last 20+ reloads with some of the 458 ones going beyond 30 - go the belted big bores!!!