When you pull an expander button out of a case, it can change the dimensions by stretching the brass. It is alot smoother to run a mandrel in and I never saw it change the dimensions of a sized case except the diameter of the neck. MattI'm having trouble understanding the difference in a expanding mandrel die like Wilson and the expander that comes with my Hornady Match bushing sizing die. They seem to do the same thing. What is the advantage of the Wilson mandrel over the Hornady die with expander button?
An expanding mandrel avoids the problems caused by the expander button on your sizing die.What is the advantage of the Wilson mandrel over the Hornady die with expander button?