I recently bought an interesting gun at Cabela's. Apparently it had been there for some time because no one knew what it was.
It's an 1870 Frank Wesson single shot, centerfire smoothbore with a 24" barrel. There's a liner in the barrel that stops approx. 1.9" from the breech, forming a chamber. The liner is also smoothbore.
The breech measures .375" diameter. The liner, from the end of the chamber to the muzzle, is .358" diameter.
The serial number on the butt and inside the grips is 12. The serial number on the barrel stub/lug is 2303. There is no number on the barrel itself, or on the removeable stock. The removeable barrel is attached to the frame by a screw.
I posted it on the ASSRA forum and a member looked through his 3 volume Wesson set and found some good info on Wesson pocket shotguns. Apparently there were fewer than 25 made, all special orders. The authors of the Wesson books knew of three. Taxidermists and small bird hunters used them.
I made up a few black powder shot shells with .357 Mag brass, and a few others with round balls sized to .356. To make up the difference in the chamber between the length of the .357 Mag case and the beginning of the liner, I cut a spacer from a .357 Mag case. A .357 Max case would be better. A Stevens .38-55 even better. It shot well.
The barrel rotates to the right for loading and unloading.