I use a Hornady FL Die set & new RP 8x57 Brass. I neck them straight, then size in the Hornady FL die to place the shoulder in the proper location for 0 stretch on fireforming.
A "nose tapered(grinder)" .44 mag belling die can be used for expanding the new brass in one pass. I inside lubed the necks and in one pass, necked them straight with zero losses. I did not anneal them until after fireforming them.