That's an early muzzle-loaded, flared muzzle (or the entire bore) shotgun.
See the related Wikipedia link listed below for more information:
The pirate had his blunderbuss loaded for the fight yet to come.
ks
The highwayman backed off from the coach and spurred his horse down the road when the coachman raised his blunderbuss.
a musket
A problem.
blunderbuss
during the east Guam war
noun, a muzzle loading firearm
Lords of War - 2012 Blunderbuss Blowout 1-3 was released on: USA: 30 January 2013
There are not a lot of places to purchase a vintage blunderbuss. However, one can purchase them at the websites Sale-fire, and eBay. Another place is a local antique shop.
depends on : condition : maker :year made
It's an early kind of gun, so it was used for shooting