I am getting ready to start load development with some new brass in my 7RM. This will be the first time I have started with new brass in a belted mag. In order to prevent excess stretch in the new brass I plan on one of the above to hold the base of the cartridge against the bolt face. I have seated the bullet into the lands on some standard cartridges for this purpose before, but am thinking about the shoulder so that I can experiment with seating depths while fire forming. If you have a preference, can you elaborate. If the shoulder is the way to go, what is your method. I grasp the idea, but would like to here your practices. Thanks in advance. I appreciate the knowledge available here.