What is Choke on a Shotgun and what does it do?

What is a choke on a shotgun and what does it do

Shotguns have come a long way since their inventions and have been incredibly versatile tools for sport shooters and hunters alike. However, there’s one part of a shotgun that is often misunderstood, even by a lot of the more experienced shotgun shooters. That is the Choke!

Look, if at any time you want to purchase a gun, it is important that you understand some of the key factors that you should be considering. And when it comes to shotguns, the choke tubes are one of the essential features that make these tools so handy.

At first glance, the shotgun choke may look like just another accessory but in reality, it is one of the most important parts to get right when using the firearm.

The choke also happens to be one of the most wrongly labeled parts of a shotgun. In this article, we will look at what a choke does, what it looks like, and how you can find the right one for the right job. Understanding what the choke does is key to your shooting success.

So, What is a Choke on a Shotgun?

So, What is a Choke on a Shotgun

A shotgun choke is a tube that is placed over the muzzle of a shotgun. Its main function is to improve a shotgun’s accuracy by altering the spread of the shot.

Put simply, a choke is a device at the end of a shotgun barrel used to change the spread or pattern of the pellets when fired. Another way to describe a choke is as a constriction of the barrel at the muzzle end, designed to control the spread of the shot.

Chokes are a part of a shotgun that modifies the spread of a pellet shot from a shotgun.

According to Wikipedia, “Choke is a word in shotgunning to describe using a shotgun with its barrel constricted at the muzzle.” Chokes are generally used to make it easier to shoot a shotgun by creating a tighter pattern and closer range.

Therefore, a choke is, essentially, constriction or controlled obstruction. It is an attachment at the end of the shotgun designed to control the spread of the shot that is released when the gun is fired and provide tighter shot patterns and longer range.

What Does the Choke Do?

What Does the Choke Do

Well, it works as it sounds. It chokes. That is, it works by constricting or narrowing the barrels of a shotgun. A choke basically controls the amount of shot that is released when the gun is fired, which is accomplished through a constriction or controlled obstruction.

The choke can be used to adjust the spread of the shot to make it more or less dense. In other words, chokes can be interchanged to provide different patterns, depending on the desired use.

For example, a tighter choke (one with a smaller diameter) will result in a more focused and tighter pattern of shot, while a looser choke (one with a larger diameter) will result in a wider and more dispersed pattern.

You may also consider a shotgun choke as a camera aperture that increases or decreases to provide more or less light. It brings about the effect of reducing the spread/pattern to provide a greater density of pellets. But how does this help target shooters and game shooters anyway?

The Function of Chokes in Target Shootings

The Function of Chokes in Target Shootings

As we have just mentioned, a choke on a shotgun is used to change or alter how the shot is distributed when it leaves the gun. For target shooting, an ideal pattern is one that is as large as possible yet thick enough to allow multiple hits on the clay or target, at a specific range.

Chokes are mostly featured in target shotguns and modern hunting to enhance performance. Depending on the target’s size and range, and whether it is moving away from the shooter, across, or towards him, the choke can be used to shape the spread of the shot to improve range and accuracy while providing the ideal pattern of pellet density.

Skeet shooters firing at closely spaced targets may employ 0.005 in or 0.13 mm of constriction to achieve a 30 in (75 cm) diameter pattern at a range distance of 20 meters.

Meanwhile, trap shooters may employ 0.030 in (0.75 mm) of constriction to create a 30 in (75 cm) diameter pattern when firing at distant clays moving away from the gun at a range distance of 35 meters.

Special chokes designed for hunting turkeys (a practice that often calls for long-range shots at the neck and head of the bird) can reach heights of 0.059 in (1.5 mm).

It is good to note that although using too much choke and a small pattern can make it hard to hit the targets, using too little choke, on the other hand, will create large shot patterns with insufficient pellet density to break the clays or targets.

A shotgun choke should be tailored to the target’s size and range. Usually, shotguns meant for defensive purposes or covert ops are fitted with cylinder or enhanced cylinder chokes for the largest shot pattern at rather shot defensive ranges. There’s no constriction in cylinder barrels.

One more thing to know about chokes is that they’re most commonly found in shotguns, but they’re as well utilized in some pistols, rifles, and even airguns to enhance performance. In fact, the bore diameter of some.22 LR competition rifles is constrained close to the muzzle.

How Does the Choke Affect the Pellets?

How Does the Choke Affect the Pellets 1

With a cylinder bore barrel, the pellet stack will be subjected to two forces: The first one is where the gasses expand due to the explosion of the powder, which moves the pellets down the barrel. And the second one is when the air resistance obstructs or constricts the pellets from moving forward.

Therefore, in absence of the choke, the pellets will tend to disperse and travel in divergent directions. But that’s where the choke comes to play; it helps to limit/control the dispersion of the pellets.

It achieves this by altering the pattern of the pellets at the end of the barrel. The cylindrical column of the lead is actually transformed into a considerably more aerodynamic mass, with a shape similar to that of a truncated cone.

This enhances compatibility, particularly in the front section, which makes it easier to cut through the air with minimal friction. Moreover, improving the pellets’ compatibility also helps to reduce the spaces or crevices between them and the likelihood of air getting through.

In other words, the choke lowers the dispersion effect, which is important for keeping the spread regular and compact, when at greater ranges. Note that delay tends to decrease with an increase in the residual velocity of the pellets, particularly at long ranges.

Following muzzle discharge, the pellets’ trajectory gets more and more affected by the choke’s constriction, and therefore they spread radically, resulting in a traversal distribution that serves as the “spread” in this context.

A shooter can improve accuracy or firing range by altering the little tube at the front part of the barrel. A hunter can as well customize their firearm for particular hunts by adjusting the choke tube.

The diameter of the bore inside a barrel can also be increased to create a “jug choke”. Screw-in chokes can too be installed inside a barrel to develop chokes even after the barrel is produced.

Fixed Chokes vs Interchangeable Chokes

Fixed Chokes vs Interchangeable Chokes

Note that for a successful hunt, you will need to have the right choke tube. For instance, turkey hunting may require a different shot pattern and range compared to dove hunting.

Chokes can either be fixed or interchangeable. A fixed choke is installed on the gun by the manufacturer, whereas an interchangeable one can be changed by the user. The two main types of chokes are cylinder and improved cylinder.

You will find these two types on most modern shotguns. A cylinder choke has a constriction that is uniform all the way around. Whereas an improved cylinder has a constriction that is larger at the end and then tapers back to the same diameter as the cylinder choke.

One manufacturer of interchangeable chokes, Briley Manufacturing, employs a conical part that is about three times the length of the bore diameter so that the shot is gradually compressed down with the least amount of deformation.

The cylindrical section is typically 0.6 to 0.75 inches (15 to 19 mm) shorter. Note that you can still achieve the same desired results with fixed chokes as would with interchangeable chokes.

The History of Shotgun Chokes

The History of Shotgun Chokes

The history of shotgun chokes can be traced back to the early days of firearms. Chokes were originally designed to help improve the accuracy of shotguns by constricting the diameter of the barrel. This helped to create a tighter shot pattern, making it easier to hit targets at longer ranges.

Note that initially, all smoothbore firearms were fitted with barrels that had regular cylinder bores; their core and muzzle diameters were the same. While this was suitable for achieving spread at ranges up to 25/28 meters, it could however produce irregular spreads for distances beyond 30 meters.

So, in 1873, European hunters realized that Americans were using an inventive technique to bore shotgun barrels.

This technique involved adding a choke section toward the end of the barrel to achieve more compact spreads, which produced significantly better ballistic performance compared to the standard, typical cylinder bore barrel.

As such, it turned out that using shotguns with extremely long barrels was the only way to increase density and the likelihood of striking targets at further distances with an effective spread. Long barrels enhanced aiming accuracy mainly due to the great line of sight.

The most popular gunsmiths, including Rigby, Purdey, Greener, Scott, and Dougall, began doing research as soon as they learned about this new barrel in an attempt to come up with their own barrels that could constrict at the end. They later used the same in the competitions.

While this was just the beginning, it is easy to understand why chokes were a true revolution for all smoothbore shotguns, and how they enhanced effective range and optimized the spreads for shooting targets at a greater distance.

The usefulness of choked barrels for clay pigeon shooting (which was very popular at the time) was instantly evident, demonstrating that this innovation was much better than anything that had come before.

Over time, the design of chokes has evolved to include a variety of different chokes or constrictions. These days, there are chokes designed for specific types of shooting, such as skeet or trap. There’re also chokes that can be easily adjusted to change the pattern of the shot.

No matter what the purpose, shotgun chokes continue to be an important part of the shotgun performance. They help make shotguns more accurate and can be customized to fit any shooter’s needs.

The Most Common Chokes for Smoothbore Shotguns

The Most Common Chokes for Smoothbore Shotguns

There are many different types of chokes but five of the most common often used by major firearm manufacturers include:

  • Full Choke
  • Cylinder choke
  • Cylinder Modified choke
  • Modified (Medium)
  • Improved Modified (Three Quarters)

Chokes are categorized based on the choke value, identifying them in various ways, as is the custom in most of Europe. Historically, they were marked with the two entry and exit bore sizes in millimeters, but nowadays, asterisks, stars, or crosses are used to designate the prescribed values.

A choke with more stars or asterisks is more open and so more successful at close ranges, whereas a choke with fewer stars or just one star is often utilized for longer-range shots.

Nonetheless, every choke listed above is designed to serve a specific purpose. Of course, there are other specialized forms of chokes in addition to the standard ones, but those ones are mostly made to shoot a certain type of game and they tend to work best when used with a specific type of ammunition.

Full Choke

Full chokes are the most extreme options available for smoothbore shotguns and are primarily used at longer ranges. It can be a great choice for hunting and competition shooting as it enhances the constriction of the shot by a significant margin.

That means the pellets would reach greater ranges before spreading out.

One good thing about full choke barrels is that they can produce narrow and centralized spreads that obstruct dispersion and may even reach ranges of 50 meters. Moreover, they can reach distances beyond 45 meters when used with the right cartridges.

A Full Choke in 12-gauge firearms can produce a dense spread with an average shot percentage of 80–90% on the regular 76 cm pattern plate at 36 meters. These chokes range from 9–11 tenths and are often used for hunting as well as competition shooting.

However, this choke may not pattern well at close range. In fact, it requires a great deal of accuracy to be useful at short ranges. Generally speaking, the number of notches on the front decreases with an increase in choke tube constriction.

A full choke would only have one notch, whereas modified chokes typically have three. It is always crucial to double-check which choke tube you have before fitting it in your handgun. Otherwise, the number of notches might vary from one manufacturer to another.

In addition to that, it’s important to understand that when gauge or bore size changes, the choke limitation decreases accordingly. In other words, the choke will be less severe/extreme for lower bore sizes. For instance, a full choke on a.410 will be no more than 5 or 6 tenths.

Cylinder Choke

The cylinder choke, which really isn’t a choke at all, doesn’t warrant much discussion. In fact, it is the inverse of a Full Choke; instead of the barrel being choked, it is bored all the way to the muzzle with the same diameter.

Cylinder bore barrels are mainly used for short distances like 18 or 25 meters, which makes them ideal for shooting targets acquired at closer ranges, particularly small fast-moving clays.

There’s no constriction of the pellets as they leave the muzzle, which results in a greater spread, affected only by the wad and cartridge used. In other words, it’s a task made easier by a greater spread.

Cylinder Modified Coke/Four Star Chokes

In some hunting situations. cylinder chokes can produce excessive dispersion and spread that isn’t quite enough. This happens when shooting at intermediate ranges for instance 28/30 meters, or when hunting with a pellet size that is actually large for that specific purpose.

In such a case, a few meters of extra range might just be enough.

The best part about the improved cylinder choke is that it has a muzzle that’s 2/3 tenths of an inch smaller than that of the barrel bore. That means it creates a shot pattern density such that 50% of the shot in the cartridge will be subjected to the standard 76 cm pattern plate.

Unlike the cylinder choke, this choke can give you the ideal ballistic performance where necessary (up to ranges of 30-32 meters), especially when using long-range cartridges that can maintain spread density and conserve energy.

This choke has the same effect as a cylinder bore barrel when used with spreader ammo or a felt wad in a roll crimped case, but with the correct cartridge and tightish spreads, it behaves more like a medium choke and may be used at ranges of beyond 30 meters.

Modified Choke/Three Star Chokes (Medium)

Modified ChokeThree Star Chokes (Medium)

The modified or three-star choke is arguably the best medium choke, the most popular, and the most versatile option for the majority of hunting situations. It can also be a great choice for many competition specialties, especially for your first barrel.

It contains more construction compared to the improved cylinder choke. Slugs can still be fired from the gun, although doing so is not recommended as it could harm the choke in the long run. This is one of the most favored chokes by hunters, mainly due to its great versatility.

Modified choke is considered most effective at ranges between 30 and 40 yards, which provides hunters with devastating coverage at both close and medium ranges.

Modified Improved Choke/Two Star Chokes

This is a high-value medium choke designed to provide a long range without creating spreads that are rather too tight for medium-range purposes. It is a very common choke that’s widely used in both hunting and competitive shooting, mainly because it produces an excellent spread even with light loads.

Testing the Choke of Your Gun

We won’t dive into manuals on measurements, percentages, or ballistics; instead, we’ll focus on what your rifle can do for you. Selecting the cartridges you intend to use is the first step. If you don’t have a lot of the same kind, it may be difficult to figure out what has to be changed.

You’ll need to test the gun using a pattern plate. So take your firearm to a safe place or a shooting range in accordance with the regulations for doing so.

Then place large enough sheets (preferably 1 m2) on a wooden frame and mark the center of the sheets with visible tape to help your aim.

After that, you can begin examining the dispersion of the shot. Note that with the exception of smaller bore sizes, which should be tested at closer ranges more appropriate to the actual range of the gauge, the optimal range when using a gun for hunting is the usual 36 meters.

The ideal range for testing it is roughly 32 meters given that a 20-gauge will have about 10% less range than a 12-gauge.

Typically, a.410 is tested at 25 to 27 meters, whereas a 28-gauge is tested at a range of 28 meters. Testing spreader shells or cannons with grooved/rifled or paradox barrels will require closer ranges (normally 12–15–20 meters).

You’ll need at least five shot patterns fired under identical circumstances in terms of distance, barrels, chokes, and cartridges in order to conduct an ammunition test that is sufficiently accurate.

If you are planning to test many cartridges at once, the number of patterns can be lowered from five to three, but not any lesser.

Shot pattern tests carried out on individual sheets can be preserved by ripping the sheet off the tripod and marking it, but those performed on metal plates should be documented after each shot or cartridge.

You might want to add a reference number or code on the metal plate that corresponds to any test-related notes you may have made.

Assessing the Ballistic Performance of Hunting Guns

Assessing the Ballistic Performance of Hunting Guns

When examining the ballistic performance of guns and ammunition purposely meant for hunting, it is best to use the same combination at different ranges to check how the performance varies at typical ranges.

You will need to fire at least five bullets at a minimum distance of 15 meters, then gradually extend the distance to 25, 36, and 40 meters.

In this method, you can observe how your rifle responds to a certain choke and cartridge, evaluating each time whether at the range you believe to be ideal. At least the minimum required number of five pellets should hit the target.

In case you find that the shot patterns are too tight or rather compact and you realize some spaces where the target could be missed or receive fewer pellet hits, it means something needs to be done. But how do you resolve tighter chokes? By making small changes, one at a time.

Assess the cartridges first and consider using different types.

When you are aware that shell load and component effects on the spread are clearly related, for example, the wad type, the pellet size, the case crimp, and the number of pellets, then you should consider testing cartridges with various wads, loads, and crimps.

You’ll realize that felt wads generally produce a more generous spread, particularly when they are rolled and crimped. The best course of action after the first evaluation of your ammunition is to test the same shot with other chokes. It turns out that, there is a ton of work to be done!

Parting Shots

Parting Shots

In a summary, a choke on a shotgun is a tube that is fitted over the barrel and helps control how much of the shot travels down the barrel and how much spreads out.

This can be useful for many different kinds of hunting. As the different chokes are changed, the size of the spread can be changed, which can help with different kinds of games.

When looking at which choke to use, you should consider the distance at which you will be hunting and the size of the spread that you need.

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Lisa Hayden-Matthews

An avid Skier, bike rider, triathlon enthusiast, amateurish beach volleyball player and nature lover who has never lost a dare! I manage the overall Editorial section for the magazine here and occasionally chip in with my own nature photographs, when required.
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