Chambered for .54-caliber percussion. Has a 5" octagonal smooth-bore barrel. Bowie-style blade is 11" long by 2" wide. Forged together with trigger guard and knuckle guard that protects the grip. Handle is walnut. Pistol issued to U.S. Navy's Wilkes-South Sea Exploration Expedition. Markings are "C.B. Allen / Springfield / Mass." "Elgin's Patent" and letters "CB", "CBA" along with date 1837. If the sheath that was issued with this knife pistol is included and in sound condition, it would add approximately $700 to value. There were 150 manufactured for U.S. Navy in 1838.