I just now completed my latest project, this one for me. And just in time for July 4th.
Material is SS, from boat prop shafts. Barrel is 20" to the breech, muzzle bore is .780, but the barrel bore is stepped from 1.3 down to .937. This being NJ I do not want a bore that is one size or else I have a destructive device. This baby is BP 10ga blank only. The breech block slides in vertically, this has a lanyard release, my others where fired with a mallet.
The carriage is Black walnut from a buddy, trying to darken the light pieces to match the dark, was only partially successful. But overall it can out as I liked.
Here's the stuff.