This blunderbuss has no visible maker's marks but is marked with what appear to be English proofmarks at the breech on the left. The breech also has a series of dots and round stamps. The heavy nature of the gun and its large bore size suggest it was mounted on a boat. Lewis and Clark's Corps of Discovery mounted large bore blunderbusses on their some of their vessels including the flat boat since they produced a wide spread containing more projectile's than the soldier's muskets or rifles and were easier to load. They were also used as signal canons. Though the muzzle is lightly belled on this example, the bore is relatively straight and measures just over 1 3/4 inches across making the blunderbuss essentially a 1 bore shoulder fired cannon. The breech has a integral notch for sighting.