This massive sized barrel is called a “muset bore” and is designed to fire the same ball as the Brown Bess musket, making the ammunition interchangeable with both. This combination feature was employed in the old west of American with the invention of the caliber 44-40 where the Winchester rifle could fire the very same ammunition as the 44-40 caliber Colt or other revolver. This example also has a 9 inch octagonal barrel. there is some surprisingly delicate hand done crosshatching on the grip. there is a silver oval escutcheon at the wrist and a sliding safety..