Shotgun Choke Systems

Just about all of the shotguns sold today will have barrels threaded for one of several choke tube systems. This was not always the case and many older shotguns with have fixed chokes.

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Identifying the degree of choke

Choke tubes are often marked by small notches in the end of the tube , which allow the user to see what choke(s) is in the gun by looking at the muzzle. Browning and a number of other manufacturers use this system

Alway make sure that a shotgun is unloaded and the action is open whenever trying to identify a choke tube by its markings or when changing a choke tube.

Choke Tube Notch System

Never fire a shotgun threaded for choke tubes without the choke tube(s) installed. Besides damaging the threads at the muzzle, the shot and wad column can catch on the threads creating dangerous pressures.

Shotgun Choke Tube Systems

The following Shotguns, which use screw in choke tubes, can use Winchester Win-Choke, Mossberg accu-choke or Browning Invector choke tubes interchangeably.

Cutts Compensator

Among the first changeable choke systems available for shotguns was the Cutts compensator, which was threaded to use Lyman choke tubes. These were put on a number of pump and semiauto shotguns starting in the 1940's and are still available today.

Chart for Lyman Choke Tubes
Degree of Choke Lyman No.
Spreader or Skeet .820
Improved cylinder .755
Modified .725
Full .705
Super Full or Long Range #1 .690
Mag. Full or Long Range #2 .680

Poly Choke

The poly choke was generally an after market add-on, although a number of Mossberg shotguns were equipped with them at the factory. They use an adjustable collet, which can be adjusted for different choke settings which may or may not correspond to the markings on the device. Shotguns with Poly chokes should be stored with the choke the fully open position to ensure that the steel petals don't gain a set .
The Poly Choke II is designed to screw into the existing choke threads of a shotgun barrel.

Identifying the degree of choke in a barrel

Most Shotguns sold today use changeable choke tubes however some older guns and some of the cheaper imported shotguns may have fixed choke barrels. Some barrels will have the degree of choke marked with letters such as IC (Improved Cylinder),M (Modified), F (Full) others may use the following marking system in which one or more asterisks are stamped on the barrel.

Markings For Barrels with Fixed Choke

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