I should be a little more descriptive. When I only neck up brass, it will chamber, just a little stiff. bringing the die down cleans up the shoulder and makes it easier to chamber, for me anyway. So not really needed, but that's what I do. It also doesn't hurt anything because like I said, the headspace on the newly formed brass ends up right where I want it.With my bolt dis assembled,I can easily close it on a new un sized case. The shoulder isn't an issue for me. I resize fired brass to 1.256"
Also went and run a couple pieces of brass just over the expander ball, not through the whole die. Still have donuts. Headspace is around 1.2570"-1.2575". Measuring the case mouth, they are at ~.2750". Measuring at the inner neck-shoulder junction, they are at ~.2735". Granted that's with calipers that are only accurate within .0005", but still.