I chronied some .45 L BP loads
35 gr BP with 200 grain (Yes that is light) slug (Lee RNFP)
Consistently got upward of 1050 fps
I shot Winchester cowboy loads and got somewhere around 650 to 700 fps
I also shot Cowboy loads from Mexico and got around 500 fps
The factory cowboy loads were smokeless powder.
Recoil on the full BP rounds was excessive so I backed off to 25 to 28. I think I remember about 800 fps from those rounds.
These numbers came from a 4 3/4 inch barrel.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson