Here's the case dimensions for the 8,15x46R:
http://stevespages.com/jpg/cd815x46r.jpgKeep in mind that there are lots of variations in case shape and bore diameter for this round. It was "normalised" some time shortly after 1900 and modern cases will be "normal" ammo specs. Previous to the "normalising", cases will vary from one manufacturer to another. Also modern dies will return brass to the "normal" size, but it may still not fit in your rifle if it's not a "normal" chamber. Hence why you should do a cerrosafe chamber cast and perhaps also slug the bore, (these varied quite a bit too, it seems). If it is indeed the 582nd proofed firearm in the month of March 1930, it might have been made late enough that current production cases will fit and you'll be a lucky guy.
