The steel base of a Star Progressive is a smaller diameter than a Star Universal. Most 9MM shell plates won't actually fit on a Star Progressive. Larger calibers definitely won't fit. Also, the Progressive is designed to drop the finished round out the bottom, and there is no place to remove a loaded round from the side. Since the 9MM round is rimless, it is held in the shell plate by its extractor groove, and cannot drop out the bottom of the machine.
You could machine the rim of the steel base so a 9MM shell plate would fit, and you could machine the rim of the steel base so the finished round could be extracted from the side. You would also need to come up with a base plug that would fit the Progressive, and a way to hold it in place.
Bruce Williams
Star Machine Works LLC