Well, since they didn't have chronys back then or high speed cameras to do a visual timing test, it would be pretty much impossible to determine how well they performed. Using a period firearm such as my .45's with available BP from today is about as close as one can get. I use cast bullets most always and, as OT pointed out, cast is cast. I make them the same way they did back in the 1800's except I SOMETIMES use pure lead rather than always like they did back then. I don't think they knew of antimony to harden casts outside of the chemists circles. I'm pretty sure the speeds were comparable to what I get today. I do think I am getting a bit more by probably 50-75fps because I use Swiss. I've never ran them over a chrony with anything other than Swiss.