I was using a Lee FCD for 45 ACP. It needed lots of experimenting to get it somewhat right. Then a strange thing was happening when using it. I could feel a strong "bump", both on the way in and out. It also needed a stronger press of the lever to crimp. It worked, but I wasn't happy.
I followed Bill's advice about getting the Dillon die and the difference is literally night and day. The crimping stage is so much smoother; initially I was thinking that it failed to crimp, that's how much smoother it was. Even after reloading about 500 rounds with it I'm still surprised when I crimp. All the other Lee dies are good. I don't know if this is everyone's experience, but it was mine.