This massive gun has a brass barrel that flares out to nearly 3 inches at the muzzle and has Birmingham proofs including a "3" bore mark. The lock has a brass cock and pan. The furniture is also brass. It is fitted with a large iron swivel. Guns like this were mounted to boats in the period for defense and signaling at sea, and smaller swivel guns that were still too large to be used as shoulder fired weapons were also used on smaller vessels on lakes and rivers, including by Lewis & Clark and the Corps of Discovery.