A duck hunter from Illinois named Fred Kimble is credited with the invention of the choke tube back in 1866. However, the idea of a choke tube did not start to slowly catch on until around 1959 when Winchester produced their Model 59 with a Versalite choke system. Eventually manufactures started to produce and tweak choke systems into what we have today.
Choke tubes are small tubes, usually a few inches long that constrict the disbursement of shot as it exits the barrel. The way choke is determined is by subtracting the diameter of the bore of a choke tube from the diameter of the bore of the barrel. Let’s say the diameter of the inside of a 12 gauge barrel is .720, and the diameter of the choke tube is .700. That is a .20 of an inch constriction of the shot as it exits the barrel which makes this choke a “Modified” choke size.
The chart below shows the diameter of the many different size chokes.
|CHOKE SIZE||10/12/16/20 GAUGE||20/410 GAUGE|
This chart shows the percentage of shot that is placed inside of a 30” circle fired from various distances indicated in the three columns.
|CHOKE SIZE||20 Yards||30 Yards||40 Yards|
What does all of this mean? A tighter choke, “Full” for example, will keep the pellets in a tighter pattern as opposed to “Cylinder” which will spread the shot pattern out. A Full choke would be used for making a long distance shot; since the pellets are grouped tightly they will travel farther and keep more pellets in the kill zone. A Cylinder choke will quickly spread the pellets which will provide good coverage of pellets in the kill zone for close shots.