Les, thanks for that. Makes perfect sense, I just never considered it with brand new un-fired brass. If I use the CH4 dies to form cases from 8x57 brass, the full length sizing die sets the shoulder in the correct position for a 0.004" headspace, however the neck is a little short. I am just getting the expander die Zenit coated at the moment but as soon as it comes back I will try that.
Depending on the price I would still be interested in some PPU brass if available so if you could find out when you get a chance, that would be greatly appreciated.

Waidmannsheil.