Forster sizing dies:
http://www.forsterproducts.com/Pages/dies.htm
" Expander button which solves the age-old problem of keeping case necks concentric during the neck expanding operation. The Floating "E-Z" Out
Expander corrects misalignment of the center spindle assembly and prevents the case neck from pulling off center
during the expanding procedure. As shown in illustration (A), the "E-Z" Out Expander button is in an elevated
position near the neck of the case. In illustration (B), the case is withdrawn from the die, but most of the neck is
still supported in the neck sizing portion of the die, which keeps the axis of the neck and the case in alignment."

So is it possible to get the exapnder ball too high?
And still be smothe?

I am not getting the .0015" concetricity that I was once. I am now getting from .0015 to .006" concentricity.

Yes, if the expander ball is set too high in the die you will find it`s in the case neck / shoulder area when you try to size your case.
Either it will not let you size or will not let you pull the case back out if you do get it in the die.
Have you checked the case neck wall thickness? I`ve found Win, Rem brass seems to have a variance of ~.004 /.005 in the walls. The neck may be straight on the inside and show run out on the OD, or the thick brass may pull the ball off center and induce run out when it opens the necks after sizeing.

[ 11-03-2002, 03:59: Message edited by: Ol` Joe ]

Thanks for the response.
This is WW brass from heaven.
I cannot detect any variation in the neck walls.
It is all .015" neck thickness.
The 257 Roberts Ackley Improved formed brass looks great.

Maybe I forgot to put the expander ball in the die last time...