Been reloding for years but just started with the 460. I've been using various brass but have experienced case seperation and cracking about 1/3 the length of the brass up from the base. I've cut some in half and after only two or three firings they show a ring where seperation is starting. The brass measures at the proper over all length and I'm not shooting hot loads. I also shoot a 500 and have up to ten firings on some of that brass with no issues. Any one else had problems with 460 brass? What's up?