I have used 8x56R brass in the 8x58RD,its 0.3 to 0.4 mm to thin over the rim. blowing out after the first load it remained but of course its a question of pressure.
there was once a site for reloading the swedish machine gun cartridge 8x63 http://old.municion.org/8/8x63Bofors.htm

there were some K98k rechambered for this round for machine gun crews so they use the same ammo. plain and simple 3006 brass was used whats 0,5 mm under size at base.
for fire forming the base was wrapped with tape so it stands centered in the chamber and blow out uniform.