Send them to Lee. It's the dies. I'm not trying to start a war or anything, but sometimes you do get what you pay for. Don't get me wrong, I have a few sets of Lee dies myself, but Hornady and Dillon are much nicer. It would be harder to explain beyond that, except to say that if you load a few rounds with the Lee dies and then switch to the Hornady or Dillon, you can tell the difference.
The last set of Lee dies that I got was the four die set in .45 ACP. While I was loading, something kept binding. Something similar to what you are experiencing, but not to that extent. It turned out that the FCD was binding. Maybe it was sized too small. I swapped it for a Hornady and guess what. The problem went away. The Lee dies are inexpensive because corners were cut someplace. That's not always a bad thing, but sometimes it shows.
Lee is a good company. They'll make it right.
The last set of Lee dies that I got was the four die set in .45 ACP. While I was loading, something kept binding. Something similar to what you are experiencing, but not to that extent. It turned out that the FCD was binding. Maybe it was sized too small. I swapped it for a Hornady and guess what. The problem went away. The Lee dies are inexpensive because corners were cut someplace. That's not always a bad thing, but sometimes it shows.
Lee is a good company. They'll make it right.