How Does a Crossbow Work

If I were to ask, close your eyes, and imagine the first thing that comes to your mind when I say the word “Crossbow,”? Wookies, perhaps, maybe vampire hunters, or even some famous hunters.

Even I would think about any of these as Television shows have done an excellent job of molding us, but I’d not consciously think of crossbow’s impact and mechanism.

You see, crossbows are popular weapons that have been around the world for thousands of years — and their origin can be traced back to ancient China (I’ll talk about this in a bit).

This popular weapon kind of looks like a cross among a bow and rifle with a trigger mechanism, just like modern firearms.

Therefore, a crossbow works just like a bow where it shoots projectiles with the help of a fast-moving string. Plus, it has a trigger and stock similar to a rifle.

Due to these connections, many individuals think of the inventor of the crossbow as if he managed to take some parts off a bow and rifle to create this unique weapon.

But you and I both can agree that it’s not the case here. What’s more, is their working mechanism that triggers the exhilaration levels, at least of mine.

So if you are pondering how this favorite weapon of yours works? Then you, my friend, are at just the place.

And without taking much time here, we should plunge deeper right away.

So What on Earth are Crossbows?


I’d say it’s a good idea to brush up the nitty-gritty of crossbows before jumping directly into the working mechanism of these weapons.

So, what’s a crossbow?

As the current knowledge serves us, crossbows are much like a bow, where they have a string that is drawn backward to launch a crossbow bolt (arrow) towards the target or whatever it is that you’re shooting.

That said, the design of crossbows is much more sophisticated than a bow or even a compound bow, and modern crossbows are way more complicated than the early models.

Crossbows have several features that enhance the efficiency of this weapon. And you can even think of crossbows as a blend of a rifle and a bow. But crossbows came way before the first rifle.

To simply, crossbows are just a type of bow (horizontally mounted bow) on a long stick, and it shoots arrows or, in this case, bolts.

Keeping that in mind, modern crossbows have modernized in design, construction, and functionality. And the recent models significantly differ from the original or the ancient ones used by our ancestors.

A Tad Bit of History About Crossbows

Crossbows were introduced during the Warring States Periods into the Chinese Warfare. However, archeologists have found a 2,500-year-old grave of Chinese soldiers with crossbows, and many archivists expressed a belief that crossbows were in China during the 2,000 BC period.

Crossbows were also prevalent in Europe all through the Middle Ages. And in both the Mediterranean and Chinese societies, the description of a crossbow remains the same.

They had horizontally mounted bows to stocks or tillers, and through a notch, in the tiller, the bolt or arrow used to travel and hit the target. And both the styles had the same drawing methods, and one of the common was the stirrup.

Where a person has to hold the crossbow with his foot whilst drawing the string with the hands, and similarly, both the styles of crossbows had a trigger to shoot the bow or release the bolt.

At the core, a crossbow is just the improvement of a barebow that was existing for centuries. Simple bows were then improved with better shape and materials to make the weapon more powerful and efficient.

However, shooting an arrow required strength, speed, agility, and even some skill. And becoming an adroit archer was no easy task back then and even today. It takes years to master archery, and archers are profoundly admired for their skills.

Back in the days, children were taught archery from childhood so that they’d join the army and become skilled archers to fight along their side.

As archery was not an easy task, to compensate for the skill gap and increment the recruit count for the archery position in the army, the concept of the crossbow was invented.

That was the initial idea, to make things easier for new people so they can join the army as an archer. Compared to standard bows, crossbows were much simpler and straightforward to use and required less strength, so even female warriors could use them without a hitch.

Let’s Talk About the Physics included in the Crossbows

Once the military started to use reliable firearms, crossbows ceased to exist, and such guns began to surge in popularity.

However, crossbows are still very popular and widely used today, as well as during the 15th and 16th centuries. As I noted before, today’s crossbows are far more sophisticated than the ones that were manufactured initially.

Talking about their material, it’s primarily strong and robust as well as lightweight and compact. Nowadays, crossbows even have an attached scope and other gadgets that not only improve the accuracy of the weapon but also the efficiency.

That said, no matter how complicated a crossbow is, at its core, the functionality and the idea are just the same as a basic bow. In similar terms, a bow is just a spring.

You see, when you press a spring down, we all know how it responds to that force by bouncing back and expanding to the original shape. Similarly, if you pull the ends of a spring in an opposite direction, you can expect the same result, but instead of bouncing, it will contrast back to the initial shape.

In the physics realm, this is called the spring’s “Elastic Potential Energy” — that simply means it stores energy when you are pulling the shape as it’s changing the form. When you are pulling the ends of spring, this energy is stored, and when you let go of it, the stored energy gets converted to Kinetic Energy.

This kinetic energy lets the spring get back to its shape and even bounce depending on the force you’ve inflicted.

Now, this same thing applies to a bow as well. When you draw a bow by pulling the string towards your ears as well as the bow’s limbs tips towards yourself — you are actually changing the shape of the bow towards yourself by your strength to pull it back.

And once you release the bow, it springs back to the initial shape, and the string goes backward towards its original position. The movement and energy created by your actions propel the arrow from your bow towards the target or whatever it is you are aiming at.

Now talking about the energy of the bow, there are two deciding factors for the amount of energy your bow can hold. These factors are none other than Draw Weight and Draw Length.

Talking about the draw weight, it is simply the amount of force you are needed to pull the bow at full draw. Therefore, it also means that the farther you will pull, the weight of your bow’s draw will increment.

As for draw length, it’s just the distance between the string when you are at full draw and when the bow is at total rest.

Thus, to calculate the total amount of energy your bow can withstand, all you have to do is multiply the draw weight with draw length and divide the outcome by two.

To put it another way, the overall strength of your bow generally depends on how far you can pull the bow back and how hard it is for you to pull it.

For this strength that you’re required to pull the bow, different manufacturers name it the energy of your bow and the velocity of your arrow.

Speaking about the energy of your bow, it is generally gauged in either joules or foot-pounds. And as far as the velocity of your bow is concerned, the measurement is typically done in feet or meters per second.

There are many factors that have an impact on your bow’s draw weight and draw length, let alone the velocity of your arrow.

One such factor is the size of your bow. Simply longbows are way powerful and more robust than short bows.

Another factor that has some impact on your bow is the shape. Earlier, the bows used to have just a simple curve of wood. Generally, the recurve bows used at the competition these days have limbs that curve towards the archer, and in turn, reduces the brace height.

Meaning the distance between the string and the bow is shortened, and thus the arrow gets a tad bit of extra momentum when the string comes to rest after the release.

Lastly, the composition of your bow also plays a role. Your bows’ tensile strength and density are the deciding factors for the energy your bow can hold and how well it can get back to the initial shape after release.

Typically, longbows were made from a strong and elastic wood called yew. And many modern bows have different materials and parts, out which some parts are more rigid and flexible than others.

You might be reckoning what all of this has to do with a crossbow? Well, whether you know it yet or not, but all the concepts of physics that apply to a bow — are applicable to crossbows as well.

When talking about crossbows, the larger ones are way stronger and powerful than the smaller ones. Back in the days, older crossbows used to utilize steel limbs, but the modern ones have more flexible and robust material for the limbs, and that’s fiberglass.

Most of the crossbows have all the same safety, loading, and firing procedures.

Parts of a Crossbow

The crossbow is the most remarkable weapon utilized by many hunters and professionals. There are certain parts that a crossbow contains that help to increase the draw weight and length. The parts are as follows.



Consider stirrup as a metal frame that is in the front of a crossbow. The stirrup’s primary purpose is to secure the crossbow whilst you are cocking the bow by using your legs or feet inside it.



A vertical body of your crossbow is what stock is called, and you can see all the other parts that you see mounted on your crossbow are actually on the stock. The foregrip is the front part from where you hold the crossbow, and the back part that lays on your shoulder is known as buttstock (a pretty weird name, right?)



Just like limbs are the hands of your bow, in crossbows, they are more like wings. Your crossbow gets the flexibility and energy storage to release the bolt from the limbs. You might have seen modern recurve bows with curves that are away from the users, whereas the compound crossbows have a little complicated system that has a cam and pulley.



This one is just the same as the bow, a string that connects the limbs and works as the medium to transfer the energy to your bolt when you release it.


Where you mount your bolt and the bowstring moves over it is the Rail part, it is generally the upper part of the foregrip.



Lastly, the mechanism that makes crossbows like rifles, the trigger system. When you press the trigger, it releases the bolt by releasing the latching that holds the bowstring before you shoot. The trigger system also consists of safety that forestalls any sort of mishaps or accidental shooting.

How Does a Compound Crossbow Works?

Compound Crossbow

Presently, there are two principal types of crossbows, and we all know the name compound and recurve. Out of which, compound crossbows are more popular, just like the bow version of the weapon.

Recurve crossbows are the most ancient ones and are known around the world. As the term suggests, the crossbows have curved corners that are pointing away from the user. These curves also work as locks that forestall the flocking of the string when you release the bow.

At first glance, you’ll find nothing much on a compound crossbow. You load the bolt and click the trigger to release your shot. Just like a bow, right? Yes, the concept here is the same, but the execution is not.

If you scrutinize closely, you’ll find four cams and double strings in most of the compound crossbows. These cams and multiple bowstrings increase the tension of your string and provide an excellent shooting experience.

It is because the bowstring routes through cams that generate more kinetic energy that results in higher speed and more vital shots.

How Does a Modern Crossbow Works?

Modern Crossbow

Before proceeding, what exactly is a modern crossbow? Well, to simply put it, all the crossbows that you are looking at in the market are modern ones.

In addition to this, there are typically three crossbows in the market: Compound, Recurve, and Repeating.

Where repeating crossbow is the least popular amongst the three, and to be honest, it’s not that modern as well.

Similar to compound crossbows, recurve crossbows also come with cams and many of them. The discernible difference between recurve and compound crossbows is that the recurve ones require more force to draw and also produce more noise.

I would highly recommend avoiding recurve crossbows if you are planning to get a crossbow for hunting. If you do end up opting for a recurve crossbow, ensure that you are utilizing a noise dampener along with the bow.

The shooting part is familiar; you have to load the bolt on the track, pull the string, and cock the bow. This will create enough tension on the bowstring to launch the bolt with high and robust kinetic energy once you release the trigger.

It is a lot similar to how a gun works, but here it is kind of slower and less powerful, yet more noise.

How Does a Repeating Crossbow Works?

Repeating Crossbow

When talking about crossbows, they do take a bit of time to reload, and this time is only elevated if the draw weight is higher. But what if we can deal with that? Well, that’s the whole concept behind this type of crossbow.

You see, as the name implies, you can use this crossbow to fire more than one bolt per round. You can think of this weapon as a mini machine gun where you load a ton of bolts from the top and keep shooting.

But what’s the logic behind that? The basic principle of a repeating crossbow is just stacking arrows. Here, rather than pressing the arrows down with your hands, you’re loading the arrows on a plate that pushes down the arrows through spring pressure.

And rather than placing the repeating lever on the top, it’s placed below your crossbow.

All you have to do is pull the repeating lever every time you shoot, and it’ll auto-load the bolts and get them ready to fire again. Here you are not using the stirrup method where you have to use your feet after each shot.

You see, it is simple but not that effective when it comes to crossbows in general. These crossbows don’t come near recurve or compound in terms of power, and thus you’ll see many individuals opting for compound crossbows.

How Does a Pistol Crossbow Works?

Pistol Crossbow

Pistol crossbow? What? If this is what came to your mind, then yes! There are pistol crossbows out there that work exactly the way they sound.

Pistol crossbows are excellent weapons for close combat shooting, and they are kind of similar to pistols. Therefore, you can use the crossbow in one hand, just like you’d with a pistol.

However, you don’t get large rounds with this type of crossbow as you’d with a pistol.

Don’t think the mechanism here is different than in other crossbows; it’s just the same. You load the bolt on the flight track, draw the bowstring, and shoot. Howbeit, here you don’t utilize a cocking aid.

To be honest, you don’t actually need a cocking aid; you’ll use your hand to load the weapon. That said, they are not heavy and can be easily held in one hand.

You cannot expect more powerful shots from these crossbows, and due to their size, they are not the powerhouse like a standard crossbow. They do come in handy when you switch the fight from range to close-combat.

How Does the Trigger of a Crossbow Works?

Trigger of a Crossbow

As we all know by now, most of the crossbows these days come with a trigger system just like modern firearms. The trigger makes you feel that you are familiar with it.

The very purpose of the trigger is to hold the bowstring once you load it, and that’s why there is a safety mechanism with the trigger that doesn’t let you fire accidentally, as you don’t want to shoot a bolt without your consent.

The simple mechanism here is, when you press the trigger, it loosens the bowstring, and it releases your bolt with higher kinetic energy gathered from the tension and the limbs. That’s all the surface science behind the trigger system.

Yes, I know, of course, there are many other physics involved, but I am not a scientist. And I don’t want to bore you to death by teaching you physics here, and you already have a lot on your plate.

To cut a long story short, the trigger is like a pistol or rifle, and when you pull it, it sends signals to the chamber where the trigger is holding the string and releases it.

How Does a Scope of a Crossbow Works?

Scope of a Crossbow

When it comes to scopes of crossbows, I have only one thing to say — they are literally underrated. I see many people mulling compound bows or recurve bows, but seldom does anyone think of scopes, and many people even overlook it.

Yes, I do understand the basic argument that crossbows are not excellent for long-range hunting, so using a scope doesn’t make any sense.

However, scopes do a lot more than just providing you a magnified vision. Scopes help you with illuminated reticles that will make you shoot better as you can see better in low light. Not only that, but scopes also improve your accuracy, and that’s certainly what we all love in archery.

The scope of a crossbow is similar to the riflescopes, and it is generally made from two primary materials: high-quality aluminum and glass.

The aluminum is excellent for housing, and the glass is great for the lens, and in the case of lenses, most of them are typically multi-coated.

The primary work of a lens is to collect a ton of light and leave the rest on the scope. As for scope, its work includes using that gathered light and creating an image, and that’s the image that we see from the scope.

And if you are wondering how long it takes to do it, all this stuff happens within milliseconds.

How Does the Cocking Device in Crossbows Works?

Cocking Device in Crossbows

Well, if you don’t know it yet, the cocking device or sometimes referred to as the cranking device, helps you with loading the bolts by making it a whole lot easier.

As a matter of fact, the cranking device makes it easier by reducing the draw weight of your bow by 95%, which is significant. Generally, most high-end crossbows have one thing in common, the high draw weight.

So to encourage the customers to purchase the crossbows, manufacturers came with the idea of the cranking device. Therefore, even a child can load a crossbow without a hitch with the help of a cocking device.

Whereas, if you are manually loading the crossbow, it takes a lot of force to load the bow and pull the string, and it can consume your brute strength and energy.

Therefore, to decrease the amount of stress on our hands and protect them from any possible injury, the cocking device came into existence.

The device works with ropes, and you have to pull the ropes that are attached to your string and so your hands remain safe as well as there is less stress released on your hands while doing so.

As for the mechanism, the device accomplishes the job with the help of a machine inside it. The machine is not automatic, and thus to start the device, you’ll need to pull the lever.

When you pull the lever, it has some cogs that do the pulling of the bowstring for you. That’s it; this way, you will only apply some force on pulling the lever, and you’re free to rest, as the device will do the rest.

What About the Maximum Speed and Range?

Maximum Speed and Range

Many factors decide the answer to this question. For starters, how well can you use a crossbow? Because the way you use the crossbow will profoundly determine how far you can shoot with the crossbow.

Secondly, why are you using the bow? What’s the purpose? Hunting or practicing? Plus, how good is your scope?

These are some deciding factors that will help you determine how far you can shoot with your crossbow.

Generally, the speed of your crossbow is gauged in FPS, also known as Feet Per Second. Traditionally, most of the crossbows come with an ideal velocity of 300 or plus. Meaning, when you shoot your bolt, the arrow will fly over the speed of 300 plus FPS.

This speed can easily shoot your bolt over 500 yards, and thus if you are not into the target hitting or hunting, you can shoot a bolt at this speed. To simply put it, since it is difficult to aim at such a rate, you cannot hunt things, and thus this speed is not optimal.

Generally, when you are out in the open and hunting, there is no room for error. You are obliged to hit your target in the first shot (not a hardcore rule, BTW), and thus if you do end up using a 300 or more FPS crossbow, the optimal range would be around 40 to 60 yards.

You can even shoot a target from an 80-yard distance, but there are chances where the target or animal can get injured from moving or jumping, rather than killing your prey.

And honestly, I’ve seen many people who don’t have the consistency, and thus, they love to stick with 40 yards.

On the other side of the spectrum, if you are practicing with your shots, there is a margin for error, and you have the liberty to shoot as far as you wish, given that you don’t care for losing the arrow if you missed the shot.

You can easily penetrate a compressed target kept at 200 yards distance with a 300 plus FPS crossbow with a field point.

In case you are just practicing with close ranges, you’ll need to practice more to get better at longer ranges.

It is worth paying attention that the longer the arrow travels, the faster the arrow loses its energy. Meaning if your arrow is heavier, the rate of coming out of your crossbow will be slower, and it will retain its power a little better.

That said, you might be able to hit your target from long ranges through your skills. However, your arrow will not have just the energy to deliver a lethal blow.

Here’s a Video You can Watch to Refresh Things Up

By reading more and more, you are just going to end up being confused and annoyed. So I’d say, watch this video and understand the simple and ancient crossbow used in wars. You’ll realize the mechanism is just the same.

Bottom Line

If you are an avid hunter, knowing how your crossbow works and shooting a crossbow is imperative. Crossbows are strong and deadly weapons as they are compelling, and many people around the world, including me, love them and use them for hunting, shooting, and practicing.

Now that you are acquainted with how your crossbow works, I think let’s call it a day, and with this new knowledge, you can not only understand your weapon better but also probably get better at using it.

Crossbows share a rich history and heritage with them. Unfortunately, they are no longer being used for wars and are replaced with modern high-tech firearms. But back in the days, they were considered to be prestigious to use and own.

And to be honest, hunting is nothing without crossbows, and they are entertaining to play and shoot with, let alone the amusing mechanism behind the working.

Ensure that you are taking extra care of your crossbow, and it will last you for years before fraying out.

With that being said, I’ll take my leave and see you in another article; till then, keep shooting and keep hunting!