A choke is simply a tapered constriction of the shotgun bore at the muzzle end, The length of this constriction varies, usually is not less than 1.5 or more than 3 inches. This construction is normally from 5 to 45 thousandths of an inch bore. With screw in chokes, you can very easily change the degree and constriction by simply changing the choke. This allows the use of the one shotgun for almost any shooting activity.
