Properly executed in two steps the case is sized on the up stroke and the neck expanded in same fashion. Do not use a full stroke with the expander. Just enough to pass through then withdraw. Doing so minimizes case distortion the asymmetric forces associated with the shell holder geometry cause.
I'm sure that works fine. But I've found that lubing the inside of the neck of a case greatly reduces the drag as it's pulled back over the expander. I usually scratch the case against the lube pad every 5 or 6 cases to scoop a little dab of case lube into the neck. One application of lube to the inside of the case neck will deposit enough lube on the expander to keep it slick for 5 or 6 cases and prevents the case from stretching as much as it's pulled over the expander.
