My first question would be-how much did you take off the necks?? You really do not need to take off a lot if you are not prepping for a tight match chamber. And you definitely need to full size your brass before you turn your necks. You have to take the runout--out of your brass before you turn the necks. If your neck and case body arenot aligned before you neck turn, then all neck turning does is compound your problem.

Are you using your expander ball with the Neck sizer?? You could be working the shoulders too much also. The expander ball will have an adverse effect on the shoulder if it is not supported.

On any cases I turn I will normally use a collet sizing die. Your problem with the RCBS not sizing the neck down is surely what you say it is.

I am, a bit disgusted with new Winchester brass. I normally have to buy 500 pieces and sort through it to find 100 pieces that are acceptable. I just did a little study on 500 pieces of Winchester 223 brass. The results were awful. I sorted out 80 cases from 500 that I thought were acceptable to use.

I believe I understand what you are trying to do by using the different dies. I basically do the same thing(I do not use the body die). I also do not like to overwork the brass, which is what I think your goal is?? However IMO part of your problem is being caused by the expander ball. I take the expander ball out of my dies, and I use the Sinclair sizing mandrel. Tom.