I have hear that Weatherby brass specifically in that caliber is not so good.
I have notice following things:
-top loads cause some loose primer pocket, but not every brass.
-sizing brass wiht (RCBS) full lenght die, you have to use enormous power, even with exact lubrication.
I have take a contact to Norma factory, but they said that everything is ok, and I should use Norma powder and they products are "state of the art"...
Norma and Wby are same but is Nosler brass better quality? They are little bit inexpensive but unfortunately not available in Finland.