Here are the rifles, one of my 1874 Sharps (in .45-2.6") and my new Hawken. Both have 34" tapered octagon barrels (about 1 1/8" at the breech, about 1" at the muzzle), with the Hawken coming in at about 11 pounds and the Sharps at about 14 pounds by virtue of having a much smaller hole in the barrel.
Both were "state of the art" in their day, which was maybe 25 years between them. The Hawken of this pattern dates from the 1850's, when Sam was building them on his own after his brother Jacob had passed. The Sharps was, of course, 1874.
The heyday of the Hawken actually lasted much longer than that of the Sharps. The Hawken, and its very similar competitors, ruled the roost from the 1830's through the 1860's, so maybe 35-40 years before giving in to the modern breech loaders. The Sharps, however, only had about a 15 year run, before competitors like Winchester and Marlin were able to offer repeaters in the bigger rifle calibers. As long as repeaters were the smaller "pistol" sized rounds, like the .44-40, the big single shots had a place. But boy, once the repeaters could match their power, it was "game over" for them as well.
The Sharps shown is very, very similar to what Billy Dixon would have used.