I built a second close copy of Bridger's Hawken, including the 1" in 48" twist barrel, custom made by the Oregon Barrel Company. One and 1/8" by 33 1/8", rifle weighs 11 1/4 pounds, like Jim's. Some shooters get their knickers in a knot over the matter of twist, saying that a heavily loaded ball will skip over the rifling of such a "fast" twist, which is good for only light loads. Thus this demonstration.
Bottom targets were shot with 50 grains of Goex 3F and Goex 2F, note the velocities are nearly the same, with the Goex 2F faster- based on only two shots (chronograph trouble). (You can left-click the image to bring up a larger one, and left click the + sign for a sharper image).
Notice that the velocities and spread are the same on these two targets, even with different patches and over powder wads. And the first shot with the bore cleaned but not fouled, or fouled with a different powder and charge, gives a low reading.
The linen patch, wool over powder wad and 120 grain measure.
This is a heavily recoiling load, which I would not use in hunting. I like 100 grains. And Daryl, I wore that Oehler 35P chronograph out for the second time. I called Oehler, they had replaced the printer mechanism 10 years ago and will rebuild my machine and check the cables and sensors.