The tube is marked "1798/(circled)G/crown/107mm/BLACK POWDER ONLY M. ARG." and measures approximately 12 3/4 inches long with an iron-lined bore diameter of approximately 4 inches and total tube diameter of approximately 7 1/2 inches. Mounted in a hardwood bed with natural finish and iron and steel fittings. Very good overall, mostly bright finish on the brass with some spots of darker patina and some mild wear and handling marks on the bed.