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

The narrowing at the end of a shotgun barrel is called a choke. Chokes are used to control the spread of the shot pellets as they leave the barrel, allowing for more precise shooting at different distances. There are different types of chokes available, such as full choke, modified choke, improved cylinder, and cylinder bore, each affecting the spread of the shot in different ways. Using the appropriate choke for the shooting situation can improve accuracy and performance in hunting or shooting sports.