I ordered the new 300 BLK mould by Lee. It is supposed to drop bullets at .309 diameter and is a tumble lube design. My question is what powder I should use. I called Lee about it, and they didn't have any dats. Lee recommended I contact Hodgdon, but their sight only shows data for J bullets. They use H110 and Lil gun in those loads. I have shot cast bullets with these powders in the 454 cas and 500 S&W, but never in something so small as the blackout.
Suggestions?