It has been a bit of a roller coaster with the MEC Slugger. First press received from MidwayUSA was damaged and MEC ended up sending me another. Then the learning curve as there is no documentation for the specific purpose of the press, loading slugs. They send you an owners manual for the 600 Jr. Mark V and a sheet with just five troubleshooting answers concerning the three dies. Nothing on how to set the dies, which are supposedly set at the factory, nor adjust them. There are only this one sheet and one video of less than a minute. Nothing else. It has made me appreciate the Lee instructions, even more, Lee's precise style of technical writing, a skill that MEC does not achieve. The 600 Jr. manual is the wordiest press document that I've read. A lot of words that end up going nowhere.
All that said, and after 150 crushed hulls getting the three crimp dies adjusted, I'm on my way, and it is slicker than snot!

In that, this is neither a roll or a folded star crimp, but rather a folded roll crimp, it opens up a lot of possibilities that could only use the star crimp such as the Lee slugs.