The wise use of shotgun chokes can make a significant difference in the results you'll see for wing and clays shooting. In the strictest interpretation, the choke section of the barrel determines the constriction of the muzzle in order to regulate distribution of the shot charge to your target.

These days, however, a choke often refers to an interchangeable tube — often several inches long — that screws into the muzzle of the shotgun. By adjusting the density of the pellet spread, the choke lets you achieve maximum penetration depending on the distance, angle and velocity of the target.

The invention of the shotgun choke can be traced to the dawn of the 20th century. Shotgun designers discovered that tapering the inside of the barrel toward the muzzle by only fractions of an inch maintained pellet pattern integrity for longer distances. These men laid the foundation for the modern shotgun choke as we know it.

All shotguns have chokes. Some of them are permanently machined directly into the barrel for a fixed constriction, while others are interchangeable. With interchangeable, screw-in chokes you now own a multidiscipline shotgun for skeet, trap, sporting clays and wingshooting.

A word of caution: Most shotgun manufacturers use propriety threadforms — meaning that chokes aren't always compatible between shotgun brands. Likewise, in selecting an aftermarket choke, make sure the threadforms match your shotgun.

Screw-in chokes are typically known as extended and flush. The extended choke protrudes from the muzzle. By adding length, it can also provide improved pellet patterning in the same way as a water hose directs flow from a spigot. Extended chokes are marked externally for their constriction either by a letter, color coding or both for instant recognition.

A flush-mounted choke installs flat with the muzzle so it's virtually invisible. These chokes are preferred by vintage shotgun owners who want to preserve an authentic appearance or generally by others who don't like the aesthetics of an extended choke. Flush chokes often feature notches, whose numbers indicate constriction and are visible through the muzzle.

A flush mounted choke by Trulock (left) and a sampling of color-coded, extended shotgun chokes by Beretta (right).

The most popular American choke designations are full, modified, improved cylinder and skeet with the baseline measurement of cylinder (zero constriction). The choke designations are determined by the percentage of the total shot they place into a 30-inch circle at 40 yards. The tighter the choke, the more pellets should land within circle.

So with cylinder established at zero constriction, full is .035 inch, modified is .020 inch, improved cylinder is .010 inch, and skeet is .005 inch. You'll find variations on these standard chokes such as light modified (.015 inch) and extra full (.040 inch).

The typical shotgun choke constrictions, as shown by Briley Manufacturing.

Not all chokes are rated for steel hunting loads. These ratings are typically stamped on the body of the choke. Do not shoot steel or any other nontoxic ammo through a lead-only choke. Likewise, it's easy to find chokes specialized for specific prey — such as turkey and waterfowl — that provide optimal patterns for hunting loads at an customary distance.

Perhaps the biggest risk of interchangeable chokes is over-reliance on the tool. You'll see shotgunners changing chokes at every clays station, hoping that the extra millimeters will make the difference between a hit and a miss. In reality, chokes won't help you that much if your fundamental shotgunning skills are poor.