I could not chamber brass in my 300 Weatherby magnum if the diameter of the case immediately above the belt was 0.513 inches. I have a collet die sold by Innovative Technologies that will resize the case immediately above the belt. The die is expensive, approximately $120, but it works and will work on a number of different belted cases. I was worth the cost to me since Weatherby brass is about $1.80 a case. After running my brass through the die, it measured 0.509 inches.