Yes, Buck’s and Frank’s swivels are upper end pieces, for sure. In the group of 185 double rifles I have studied and photographed so far, there are few better than those. Thank you both for posting them. Both guns will be presented in my eventual book on Kentucky double rifles. I am writing chapters and still gathering data, so it won’t be out next week.
The lower barrel of Buck’s Angstadt IS straight rifled, not uncommonly seen in both American and German swivel rifles. There are numerous thoughts as to why straight rifling was used. I think it was to allow bird shot to be used in a barrel that might shoot a patched round ball more accurately than a smooth bore. Some who regularly shoot round balls from smooth bores dispute that.
Interestingly, in addition to Buck and Frank, others on this thread have opened their homes to me for studying and photographing their double rifles, including louieparker, jdm, mr. no gold, and OLUT. I am extremely grateful to this ALR site, which has been very important in moving my research project forward.
Keep up the good work, ALR Members!
Bill Paton (pronounced “Payton” :-)