The choke should be tailored to the range and size of the targets. For shooting most game birds and clay pigeons, a desirable pattern is one that is as large as possible while being dense enough to ensure multiple hits on the target, at a particular range. The cylindrical section is shorter, usuallyĪ choke is designed to alter or shape the distribution of the shot as it leaves the firearm. Briley Manufacturing, one maker of interchangeable shotgun chokes, uses a conical portion about 3 times the bore diameter in length, so that the shot is gradually squeezed down with minimal deformation. However implemented, a choke typically consists of a conical section that smoothly tapers from the bore diameter down to the choke diameter, followed by a cylindrical section of the choke diameter. Chokes may also be formed even after a barrel is manufactured by increasing the diameter of the bore inside a barrel, creating what is called a "jug choke", or by installing screw-in chokes within a barrel. Chokes are implemented as either screw-in chokes, selected for particular applications, or as fixed, permanent chokes, integral to the shotgun barrel.Ĭhokes may be formed at the time of manufacture either as part of the barrel, by squeezing the end of the bore down over a mandrel, or by threading the barrel and screwing in an interchangeable choke tube. Its purpose is to shape the spread of the shot "cloud" or "string" to gain better range and accuracy, and to deliver the optimum pattern of pellet density, for the particular target, depending on its size, range, aspect and whether it is traveling towards, across or away from the shooter. Ĭhokes are almost always used with modern hunting and target shotguns to improve performance. 22 LR match rifles have a constricted bore diameter near the muzzle. Chokes are most commonly seen on shotguns, but are also used on some rifles, pistols, or even airguns. In firearms, a choke is a tapered constriction of a gun barrel at the muzzle end. Illustration of the effect that different types of chokes have on the spread ("pattern") of shotgun projectiles