Re: Neck-Turning - What order to do?
I turn new necks, up onto shoulders, to head-off donuts.
If you fireform first, you've missed this donut addressing, and you might struggle to get full length of necks sized and expanded for good turning mandrel fit.
New brass is ready for expansion and perfect fit, right out of the box.
Now if you're forming a new cartridge, things need to be planned out & may change.