Standard Extended 16ga Chokes. Manufactured from quality steel with a coated black finish, these standard extended chokes are for all applicable 16 gauge shotguns. The chokes role is to constrict the barrel of the shotgun, allowing for tightened spread of the shot via the tapered constriction from choke. The available chokes in this series are Full, Modified, Improved Modified, Cylinder, and Improved Cylinder.