In terms of sanity, load the included bullet/sabot with 130gr volume (91gr weight) of Blackhorn 209 and shoot away. You can get respectable groups with that combo. Same load of powder, but shoot Parker Production 275BEs and you can get a most respectable group.
The above charge will handle most any chore needed, but, you may find slightly improved results under certain circumstances by increasing the charge weight some degree. Western Powders have yet to release their new load data for this specific rifle, but they have completed testing so far with loads as high as 150gr volume. Others, such as Bob Parker have recorded exceptional results shooting loads with the 275BE at 160gr volume. I suspect that something around that range will end up being the new top charge of Blackhorn 209 with this specific rifle. It will be head and shoulders above any load of 777.
Good Luck, I'll either see some posts about your success with this rifle, or I'll watch your award winning Darwin video. Those can be rather humorous in the stupidity of self-actions exercised by the recipients, but, I do believe all were killed except one since the awards inception.
Good Luck
