I had the conversion bearing and decided against it after repeated use. I found just threading the dies into the press as they came seemed to be more reliable and just as easy. Its not like I am running a race while reloading. Also, the dies likely will not work ie, same OAL on the seating die if used on the LNL progressive and with the conversion kit on the LEE Classic Cast, so ultimatly it seemed easier to just thread the dies in.