I neck size them only with the RCBS neck sizer. When they start to get tight, then I'll full length size them. As for the case life issue, I was still reloading Browning and Imperial cases after 15 years. I anneal my brass when necks start cracking, and they last for a long time. My loads are at the top end of the spectrum, and the accuracy of a neck sized case over a full length sized case is phenominal. Loading a belted case is no different than a non belted case, other than the fact thatyou are adding a lot more powder, and usually a heavier bullet than the magnum's standard counterpart.