Now I'm confused- is it 8x63 or 8x54?

If actually 8x54, and a fellow has an improved '08 case reamer with a .454" shoulder, the pilot could be bushed or changed to run in the .313" to .315" bore and open up the shoulder to .454". Any '08 IMP reamer will work as you don't need the neck cut, it's already there. Improving the chamber would increase the case capacity to about 60 or 61gr., same as the .284 case provides - just a thought for a unique chambering that no one else is likely to have at this time - ie: 8x54 Improved Krag. Mention that and everyone will be thinking of the .30/40 Krag case - no, no,no, it's actually ------- lots of fun.

If you went this way, a .308 die set would work, if opened up just a bit in the base as well as the neck.
Actually, the seater might have the correct neck size already - just a thought for a newish wildcat.

The ballistics would be quite similar to the .325 WSM, ie: 175gr. at 3,000fps. The shoulder would be increased from .435" to .454" - a full .020", along with the reduction in taper - a great little round.