Remember, belted cases are designed to fit any chamber even if it is dirty for safety.
The cartridge head spaces off the belt and the case body is much smaller than the chamber so it will always chamber.
After firing the first time the case will be a good fit to the chamber and does not need any excessive sizing to bring it back to SAMMI spec. all it needs is a partial or neck sizing to allow it to chamber. Going back to a full sizing or a shoulder bump will only decrease case life and degrade accuracy. (The best accuracy will normally be when the case best fits the chamber).
Whether it is belted or not, I would recommend sizing ONLY enough to be able to chamber the round. The exception to that would be if it is used for dangerous game (where your life means more than case life). You can do a partial size to fit the chamber and essentially it is no longer a belted case in function.
If I build a belted case rifle that Is intended to be used like a non belted cartridge, I head space between .0025 and .003 to minimize the function of the belt and use the shoulder once fire formed. If it is to be used as a belted cartridge, the head space will be .001 and .002 and the cases will be full length sized every time.
J E CUSTOM
