I shoot a .300 Weatherby quite a lot for a hunting gun, and I also shoot and reload .257 Weatherby. The best gadget I have for reloading those belted rounds is an adjustable case gauge from L.E. Wilson in Cashmere, WA. For full length resizing you set the adjustment about half-way between a new case and a case that has been fired in your chamber. They don't cost very much.