[Unclenick]

Well, actually, you can buy lathe turned straight wall cases. It's one way around obsolescence, but not a cheap one. Several bucks apiece. The thing that drawing cases from a disc does is work-harden the brass, which is needed at the head, and it aligns the grain structure. I expect the lathe-turned stuff starts as drawn hard brass rod, so you'd need a source of that. SAAMI drawings will provide the exterior dimensions. Interior dimensions are largely optional.

Turning the thin walls will be the challenge. You probably want to turn the inside first and insert a form with a center drilled hole and use it with a center to prevent deflection. I don't know if high pressure cases can safely be made this way? It seems to me I saw some turned .50 AE cases at a gunshow once, so 35 KPSI is doable, anyway.