Nitro Express load data always welcome. I used RL-15 with filler for a while in a .470 NE Merkel, but found I liked H4831 better in that one too. If doing it again with a foam wad filler I would use Varget, about grain-for-grain same as RL-15, but better temperature stability and less lot-to-lot variation.
Ron aka "Rip" for Riflecrank Internationale Permanente NRA Life Benefactor and Beneficiary .458 Winchester Magnum, Magnanimous in Victory THE WALKING DEAD does so remind me of Democrap voters. Donkeypox.
