Finding a reamer might get a little sticky!! Worse case is I will have to resort to the hard way, that being a surface grinder, sine plate, Harig dividing head and a good old length of hardened drill rod. I've made many splined core pins for powdered metal die sets that way (before EDM came along). Setting up a 30-06 or .243 would be downright boring compared to doing a 70+ year old obsolete foreign cartridge. Then again maybe I'm a glutton for punishment!!!