If you have a tapered expander ball on the dies you can run 6mm BR into your new dies and bingo.
I have used Lee dies in the past, but I have also been studying Redding and RCBS catalogs quite carefully to see if they yielded any further clues for me.
I see Redding has Tapered Sizing Buttons as a separate part, and they seem to address necking up specifically.
Redding's listings of dies does not say they have these tapered sizing buttons in any of their dies as standard.
So for example, I buy a set of Redding 6.5 BR dies and swap out the sizer button for the .22 to 6.5mm tapered sizer button, and then run a 6mm BR case thru the 6.5 die and I end up with a 6.5 BR correctly formed case?
Can I avoid the cost of custom 6.5 dies by just using the 6mm die with the 6.5mm tapered expander the first time, then use the 6mm dies with a regular 6.5mm ball expander after that?
To give RCBS their due, they only talk in terms of Expander dies specific to each caliber. And Lee only has a Universal Case Expanding Die for flaring case mouths to aid bullet seating.
Therefore I am assuming that of the three - Lee, Redding and RCBS - the tapered expander buttons and dies from Redding is my obvious and only option among these three companies?
One more question to round out the discussion:
"If you neck down you're stuck with Remington. Not bad brass but not Lapua. "
Is this because Lapua do not make 7mm BR brass?
One more question:
If I have to neck down, make it as few caliber sizes as possible and watch for thick or donut necks?
Many thanks again for spoon feeding this newbie a steady diet of great information.