Now that I have all the parts, and most everything is set up. The last decision still looming is the choice of powder for these. Of the twenty-some various powders I have on hand, I have no reloading data for the 300 Blackout for any of them. I’d think it would be fairly close to the 223, but I guess not. Only publication that I have with data is Hodgdon Annual Magazine.
I guess I’ll run up to the shop and get some H-110.