What is the name for the narrowing at the muzzle end of a shotgun barrel?

The narrowing at the muzzle end of a shotgun barrel is typically referred to as the choke. The purpose of a choke is to control the spread of the shot pellets as they exit the barrel, allowing for more precise and accurate shooting at different distances.

There are several different types of choke configurations, each with its own unique design and intended purpose. Common choke types include cylinder, improved cylinder, modified, improved modified, and full choke. These chokes vary in the degree to which they constrict the shot pattern, with cylinder having the least constriction and full choke having the most.

Chokes can be either fixed or interchangeable, with interchangeable chokes allowing shooters to easily change the choke on their shotgun depending on the shooting situation. A shotgun with a choke system offers added versatility and flexibility in different hunting or shooting scenarios.