One of a kind

[B. Dudley]

Yes, very interesting that there is no photo of the rifling. And they say its a 12g shotgun bore still? There is an absence of a makers mark on the rib which would suggest Remington built barrels.
I don't know enough about the use of rifled bores for shotgun slugs to say if they were in use at that time.

[Bill Murphy]

Brian, the slug of choice at the time was the "ounce ball". Several of these shells were in my family "junk box" that I found in the attic of my childhood home. They are probably still around. I would like to measure one of those balls. I doubt that they are anywhere near bore size. Users of these rifled Parkers probably cast conical bullets for use in these guns.