Thanks guys, but I'm just looking for sources for a barrel (40+ inches long, 1 1/4"-1 3/8" across the flats, and in .54 caliber or larger). I'm not interested in chunk gun shooting, the rules of chunk gun matches, etc.
Dan, you see what I have in mind: something along the lines of #124 and #129 in Kindig, or RCA #100, or the heavy caplock Fordney and the unsigned heavy flintlock rifle shown by Kaufman, and a few rifles that have been shown here over the years. I'm thinking .54 cal or larger because in my earlier tests with the .48 cal Dickert, the ball was getting blown around too much at longer ranges (compared to past experience with a .54 starting out at 2000 fps). I think that even at 200 yards, a .54 would have done better.
Actually, I kind of like the .75-.95 caliber rifled wall guns, but if I built one I'd soon find myself building a blockhouse, and I just don't have the time. . . .