I had a used set of .38/.357mag Lee dies that came kind of grungy and with a bit of surface rust...so I just took them all apart, hit them with brake cleaner, a cleaning brush, synthetic steel wool, and made them all nice and clean. Now, I'm a little confused. This set arrived on a Dillon 550 tool head as a 4 die set (Lee sizer/decapper, Dillon powder die, Lee seater, Lee crimp). When I went to put things back together, I realized I couldn't tell the last two apart. Their only markings are LEE-357MAG-G9 and LEE-357MAG-H8. Other than the difference in markings, they're nearly identical. The G9's threads start about 1 thread closer to the bottom of the die. A bit of digging online, has me thinking these are both seat + roll crimp dies (of slightly different manufacture dates), and the previous user simply had one setup with the seating stem to just seat, and the other set up without a seating stem as just a roll crimp die. Does that sound right?