Headspace on belt. Brass stretches, not many reloads, and it is expensive, long actions, bullet selection has improved in other calibers also. I have a selection of dies and calibers, if I won a 7mag, it would be sold.
On the reloading side, the headspacing/stretching becomes moot if you treat it as a beltless cartridge and headspace off the shoulder by means of FL die sizing adjustments or my favorite by using the Lee collet neck sizer. Some of my batches of 7RM brass have an excess of a dozen reloads with 160 gr loads in the 3000 fps regime.
