Some details:
Liege proof marks on the barrel, signed and dated by a previous, probably German owner on the back side of the patchbox lid.
Barrel is damascus, blank and untreated.
French set trigger, high quality workmanship (e.g. mirror polish of all lock parts).
The high front sight is a replacement. The original sight is a low brass bead with which we could not work. Front sling swivel is removed here.
I bought the rifle at an auction in Zuerich some 25 years ago.

Bore diameter is 13.35 mm (.526'').
Groove diameter is ca. 14.75 mm (.581'').
Grooves are rounded and very deep, ca. 0.7 mm or .0276'' - I do not know what this should be good for.
I now use .520 bullets with rather thick patches.
Barrel is 71 cm (28") long.
Twist length is 107 cm (ca. 42'').
One peculiar thing: the powder chamber in the breech plug only has a diameter of ca. 10 mm, so there is a distinct "step" between breech plug and barrel. Volume in the breech plug is about 40 grains of powder.
I also do not know what this shall be good for. It might be useful for upsetting some expansion bullets, but does this go together with the deep rifling?
The ramrod is steel, with a flat tip.

I will tell about shooting the rifle later.

Fuhrmann