I'm not sure what you mean. The rim thickness? If so I have some of the new BeLL formed cases and they feed through my dies slick as scum on a Louisiana pond. 95 grains of 4831, no wad. 2160fps and groups .5" at 50 yards.

I have had problems pulling the rim off with some other dies. I came to the conclusion, after I got this set, that it was a combination of sloppy fit on the shell holder and rough interior.

As in all things finesse is better than brute force. Unless the sonofabitch just won't work, than a hammer is appropriate.

But I digress.