anybody turn necks successfully at bit below the neck into the shoulder ?

Well, if you turned "beyond the shoulder" you wouldn't be neck-turning, you would be "shoulder turning". Why you would wish to reduce the thickness of the shoulder of a cartridge escapes me at the moment.

Welcome to the forum, however your first post is a bit confusing, the neck of a case is always beyond the shoulder. Why would you be needing to neck turn Weatherby cases unless you are sizing down from a larger calibre Weatherby cartridge e.g. sizing down 300 Weatherby to 7mm or 270 Weatherby then you may need to turn the reformed necks.
Weatherby case necks will be no different to turn than any other cartridge neck.

Perhaps some more detail on what you are trying or thinking of doing?

to get rid of Neck/shoulder junction Donuts

I changed the wording of my initial post guys sorry.

Found out PMA sells Weatherby radius cutters