the muzzle on a shotgun is where the bullets come out.
A muzzle loading, black powder shotgun made by Scott & Co.
Amount of muzzle constriction
A muzzle loader shotgun
From the muzzle to the end of the buttstock.
Metallic Cartridges/shotgun shells transitioned from muzzle loaders to cartridges during the US Civil War (1861-1865).
Choke.
It is called "choke". lcj
The Choke of a shotgun is the amount of barrel restriction at the muzzle end which affects the shot pattern. A full choke will keep the spray pattern of the pellets closer together farther out than if the barrel was not restricted at the muzzle. If there is no restriction at the muzzle, the choke is said to be cylinder choke or cylinder bore.
About 1" past the muzzle.
Refers to the amount of constriction at the muzzle.
That's an early muzzle-loaded, flared muzzle (or the entire bore) shotgun. See the related Wikipedia link listed below for more information:
modern firearm (rifle,shotgun,handgun), Primitive (archery,muzzle loader) Trapping