Pyrodex P is FFFG equivalent, apparently formulated for pistols. Fine in a modern inline gun though. I went ahead and bought some to try. Closing in on 777 for velocity.
here is a link to their load data on powders and pellets. Note that it’s based on 24” barrel except for the magnum pellets. Implicit that Pyrodex P is not only safe in modern rifles, it’s 50-100 FPS faster than RS!
https://hodgdon.com/wp-content/uploads/2017/01/muzzleloading_manual_2008.pdf
here is a link to their load data on powders and pellets. Note that it’s based on 24” barrel except for the magnum pellets. Implicit that Pyrodex P is not only safe in modern rifles, it’s 50-100 FPS faster than RS!
https://hodgdon.com/wp-content/uploads/2017/01/muzzleloading_manual_2008.pdf