I also agree the case isn't getting stuck on the expander, if that was the problem the casing would be a long ways out before it got stuck. It is getting stuck in the die. I have noticed that the better quality dies are far less prone to sticking and require less lube, I am guessing it has to do with the polishing on the inside of the die, where cheaper dies are not as "finished".
I also think imperial wax is about the best thing for lubing there is, if I wasn't using the wax, I would be making my own lube with lanolin and alcohol.
I also think imperial wax is about the best thing for lubing there is, if I wasn't using the wax, I would be making my own lube with lanolin and alcohol.