Does anybody have any experience making 25-06 out of 30-06 and if so did you have to do and neck turning on annealing or run across any other issues that would be good to know about before attempting this project.
You may not need to turn the necks but if you do you will need it badly! Measure the diameter of a standard fired case and compare that to the diameter of a reformed case with a seated bullet. Your dummy cartridge neck should be at least a couple thou smaller than the fired case; if not you better turn them.