I am having the same issue with my 38 supercomp brass also, I loaded brand new star line with no problems, but with once fired the die is not sizing. I am using the hornady LNL press. The dies are Lee Carbide 38 super auto. I have only loaded about 200 rounds with these dies. The carbide ring is there and in good shape. I hope your new die dose the trick, if so I will be ordering one