Just an addition to the above:
My great grandfather's 1874 vintage W&C Scott 10 Bore shotgun with 30” barrels and cylinder bore gets average 1075 feet/sec with 5 Drams of Goex 2F and 1 1/4 Oz (546 grains) of #6 shot. This is with brass cases and 9ga over powder card wad then greased 9 bore felt wads.

.......I do not use this load for hunting in this old gun, just tested for curiosity one time to see what the old (said to be) 1880’s hunters load would do.
- Mike