There's a misunderstanding of the fundamental problem. Excessive working of the brass comes from the neck section of the die being much tighter than necessary to properly hold a bullet.
That and lack of annealing.
I do not use expanders. I do use mandrels.
At least with precision ammo, the goal is to reduce variables to ensure the most consistent neck tension across all loaded rounds. This is accomplished most fundamentally by turning necks and annealing.
