Re: RCBS fl die troubles...
You might try hitting the insides with a bit of very fine emory cloth and see if that doesn't take care of it. I've seen this from time to time, and this will usually solve the proble. Best if you can chuck up the die to do the polishing, as this will keep the treatment uniform. after that, just make sure your cases are thoroughly lubed with something like Imperial and that should be the ned of the problem.