Shotgun Choke and Shot String
When a shotshell is fired from a shotgun, the pellets leave the barrel and begin to spread or scatter. The farther the pellets travel, the greater the spread of the group of pellets (shot) both in length and diameter. This spread is called the shot string. To control the shot string, shotgun barrels have a choke, which will affect the shot pattern when the shot string hits the target.