I have no idea what it is. It's still manually indexing . It seems to be missing some fail safe for the powder measure under the shellplate carrier. Edit: On closer look, it looks like it might be the BL-550 and the guy at Gun Blast mislabeled it. It's missing the primer setup as well. http://www.gunblast.com/SHOT_2012_2.htm 1/2 way down the page.