Keep It Simple Series
For the average shooter, hunter or sportsman
By Johnny Dury
Choke Tubes 101: It is Not Rocket Science
That last three inches or so of a shotgun barrel, whether the firearm has a fixed choke or screw-in choke tubes, is a simple feature that should not become a head-scratching dilemma for any shooter.
Getting down to the basics, the choke in a shotgun is designed to constrict the shot column as it leaves the barrel with an intended result of producing a more open or tighter pattern of shot pellet hits on a target at various distances.
As a general rule, typical constrictions in fixed choke field shotguns are improved cylinder, modified and full. They are established by the firearm manufacturer based on percentage of pellets from their standard test ammunition that strike a 30-inch circle set at a range of 40 yards.
Most out-of-the-box shotguns with screw-in chokes that fit into the threaded barrels of the firearm will also be in the constriction of improved cylinder, modified or full. An improved cylinder choke will produce a more open pattern than a modified choke; and a modified choke will produce a more open pattern than a full choke.
The tighter the pattern, the more opportunity there is for target trauma either on clays or birds. If either birds or clays will be taken as close range, go for improved cylinder; for medium range, stick with modified; and for long range shots, bring out full. For the average hunter, that is about all you need to know.
Once a shooter moves into the competitive arena, choke selection can get a little more complicated because of the variety of constrictions available. Some clay busters don’t feel as if they are completely prepared unless they have cylinder, skeet 1, improved cylinder, skeet 2, light modified, modified, improved modified, light full, full and extra full all at the ready.
The few thousandths of an inch difference between cylinder, which is no choke constriction at all, and extra full, which is about the tightest constriction available, can be a big difference in shooting success on the clay target range.
There is another factor that can complicate the choke issue; and that concerns the fact that each shotgun and each choke may produce the best performance with a certain load of shotgun ammunition.
In some cases, a one-ounce load of hard shot will pattern better than the same load of soft shot; and using 1 1/8 ounce or 1 1/4 ounce of shot can also make a patterning difference. The harder shot deforms less than the soft shot as it travels along the barrel and out of the choke, causing fewer flyers and keeping more pellets on target.
It is recommended that all shooters from the hunters who shoot two or three boxes of shells a year at birds to 100,000 targets-a-year competitors pattern their shotguns (all choke constrictions) with several different brands of ammunition
A little time on the patterning range will determine which choke and which ammo produces the most uniform patterns at the distances you will be attempting to hit targets.
By the Way: Dury’s Gun Shop maintains an extensive supply of choke tubes made by several manufacturers for our customers interested in working on their choke testing.