Musketoon:

The musketoon is a shorter barrelled version of the musket, and served in the roles of a shotgun or carbine. Musketoons could be of the same caliber as the issue musket, or of a much larger caliber, 1.0-2.5 inches (25-63 mm). The musketoon is most commonly associated with naval use, and pirates in particular, though they also served in a carbine role with cavalry. Musketoon barrels were often flared at the muzzle, resembling a cannon or blunderbuss.

Musketoons had a brass or iron barrel, and used a wheellock or flintlock firing mechanism, like the typical musket of the period. They were fired from the shoulder like the musket, but the shorter length (barrels were as short as a foot (30 cm) long) made them easier to handle in restricted conditions, such as with mounted cavalry or naval boarding parties.

Replica of a Pattern 1861 Enfield Musketoon.

Smaller bore musketoons matched the caliber of the muskets in service, and were generally used the same way, with single musket ball or a buck and ball load, while large bore musketoons were loaded with multiple buckshot or pistol balls (generally smaller in diameter than musket balls) and used as shotguns. It is this type of loading that is most associated with naval use.






credit: http://en.wikipedia.org