I serious dont know how you read my post neither do i even know which point you where trying to makeYou're missing the point here,normal dies expand the inside of the neck under extraction and stretch the brass,using a mandrel expands the inside of the neck under compression.
A worthwhile consideration when using premium brass
Fact is ball type are no place near to straight expenders and bushings as regards good concentric necks without over working the brass. They will however do the job with almost any brass and almost any chamber