Parts of a Crossbow Explained

Are you a newcomer to the world of crossbow hunting. Or have you been away from the sport for a few years and just need a refresher on the basics? Either way, having a working knowledge of all the components of your crossbow is both useful and critical.

Being familiar with the parts that make up your crossbow and how each part works will make it easier to maintain your bow. Proper maintenance will help you get optimal performance from your crossbow when you need it.

Main Parts of a Crossbow

Two different styles of crossbows exist – compound bows and recurve bows. These crossbows do share some common basic parts. In its simplest form, a crossbow resembles a rifle with a horizontal bow mounted to the stock. It launches a bolt (or arrow) from the rail fixed on top of the barrel instead of firing a bullet.

How does each component of a crossbow work? Here’s an overview of each part and how it functions:

A. Stock

The portion of the crossbow you hold, away from any danger points, when you shoot a bolt. It rests against a shooter’s shoulder when in use. A stock is usually composed of wood or is injection molded from plastic or other composite materials. It serves as the functional base of the crossbow, tying the barrel, trigger and sight bridge together. Stocks are available in many configurations.

B. Foregrip

Your aiming hand rests under this part of the crossbow. Foregrips help give you better control of your shot so that you don’t fire off an errant bolt as easily. It helps you steady your aim and keep lined up with your target. Some crossbows feature removable foregrips or collapsible foregrips.

C. Trigger & Safety

The trigger is what releases the string and fires your bolt. Trigger mechanisms utilize two basic designs. It is either located directly underneath the latch that holds the string in a cocked position or the latch mounted behind the trigger. A safety prevents accidental release of a bolt and may engage manually or automatically once a crossbow is cocked. Some crossbows feature a dual safety system.

D. Barrel

A component also known as a rail or track, the barrel features a grooved track on top that aligns a bolt with the string. This creates consistent accuracy each time you shoot. Barrels can be composed of multiple materials. Polymers or plastic are common material for barrels in cheaper bows. Aluminum barrels are more common in higher end crossbows. It is light and stronger than plastic and stays straight. Carbon fiber barrels are also becoming more popular because they reduce overall weight on the crossbow.

E. Risers

This is the section of the crossbow where the limbs attach. Risers come in multiple configurations. It serves a primary purpose of holding the limbs of the bow at a certain angle. Typically risers are made from cast aluminum or machined aluminum. Some crossbows will feature a magnesium riser. Carbon fiber risers are also becoming an option.

F. Limbs

These are the ends of a horizontally mounted bow. Limbs are longer in recurve bows than compound bows because the length is needed to create similar power to that generated in a compound crossbow. The string connects to the end of each limb. Limbs on a crossbow are much heavier than on a vertical bow because the power stroke in a crossbow can be more than half as short as a typical vertical bow.

G. Cams

In a compound crossbow, cams are wheels mounted at the end of each limb. The string is attached to the cams and when it is pulled back, the wheels turn. This motion bends the limbs and stores a large amount of kinetic energy, which is then released once the trigger is pulled. These wheels can be round or oval shaped. The shape dictates the draw force curve of a bow and how much energy is transferred and stored when the string is pulled back.

H. Cable

Another component that is exclusively found on compound crossbows. The cable works in tandem with the cams for the purpose of reinforcing the crossbow and adjusting its firing power. Cams act like pulleys in keeping the cable taut underneath the barrel as the string is pulled back.

I. String

The most essential crossbow component. It is what propels a bolt forward. A string will influence the crossbow’s firing power and performance. It determines the feet per second (FPS) that a crossbow launches a bolt. Commonly used string materials include polyester fiber, synthetic fiber, and natural fiber. The material is chosen based on breaking strength, weight, and stretch capability. A string must be both light and durable in order to effectively transfer maximum energy from the bow to the bolt.

J. Serving

Wound tightly around the string, a serving protects a string from the arrow retention spring which holds it in the cocked position. The serving is approximately four inches long. It contacts and rides across the rail once the trigger is activated and the crossbow is fired at its intended target. It should always be centered on either side of the latch to assure that each shot will be consistent.

K. Flight Groove

A grooved track on top of the barrel between bow and latch. The flight groove serves an extremely important purpose. It allows the arrow to lie in perfect alignment with the bow’s string. This creates consistent accuracy each time a bolt is shot at an intended target. The flight groove goes right down the center of the barrel and allows the fletching to glide down the barrel without interference.

L. Arrow Retention Spring

A metal bar designed to hold the bolt in the flight groove until the trigger releases the latch. It keeps the bolt from slipping out so that you can transport the crossbow from one location to another and keep it cocked so it is ready to fire if an animal suddenly emerges. You can flip it over or point it straight down without jarring the bolt loose. The retention spring is typically molded using steel or plastic.

M. Latch

This is the mechanism that’s designed to capture the string when the crossbow is drawn. The latch works by holding the string in place and keeps it taut until it is released by pressing the trigger.

N. Sight

Aids in aligning the bolt with the intended target to improve accuracy when a shot is fired. Three types of crossbow sights include pin and peep, red dot and scope. Pin and peep sights feature an adjustable pin as a front aiming point and a rear sight peep hole molded from metal or plastic. This type of sight does not fog up or require batteries. Red dot sights are battery operated and have one to three aiming points. Scopes are the most widely used sighting method and offer multiple options in aiming points and magnification. Crossbow specific scopes vary from a rifle scope in that they are specially designed to meet ballistic performance and vibration of a crossbow.

O. Sight Bridge

This is where you mount a sight on the crossbow and hold it in place. It is a vital feature for any crossbow. A sturdy sight bridge gives a sight a solid base and that is so crucial for achieving consistent accuracy with each shot. Some crossbows connected the sight bridge to the trigger housing. Others bolt it to the stock. Sight bridges are typically made from a strong lightweight metal like aluminum.

P. Cocking Stirrup

A metal foothold used to aid in cocking the crossbow. It is a hoop-shaped piece of metal at the front of the crossbow. You place your foot directly inside the stirrup to prevent the bow from slipping while you draw back the string into cocking position. It is mounted to the end of the barrel or riser. The stirrup also protects the end of the bolt from being damaged while on the move.

Q. Quiver

Container for carrying bolts. Quivers are available in multiple shapes, sizes, and configurations. You can mount a quiver under the bow or on top of it. Some quivers can also be mounted parallel to the bow itself or mounted parallel to the barrel. A typical quiver holds 3 to 4 bolts and includes a plastic hood to protect broadhead blades from getting damaged or causing damage.

Parts of a Crossbow Bolt

Crossbow bolts are hunting arrows specifically designed to use with a crossbow. A traditional compound bow cannot fire a bolt. They work exclusively with crossbows. The design is similar to hunting arrows, but bolts are shorter in length because of the power stroke difference with a crossbow. Most bolts range from 16 inches to 22 inches long. 20 inches is the average length.

Bolts are composed of these specific elements:

A. Shaft

This is the main body of a bolt. The shaft is typically composed of aluminum or carbon fiber. These materials are lightweight and do not splinter like wood or cheap plastic. They are also highly resistant to bending.

B. Spine

Each shaft offers varying degrees of stiffness or resistance to bending. This stiffness is termed as the shaft’s spine. Greater resistance to bending means a shaft has more spine.

C. Grains

This is the unit used to measure the weight of the shaft. Manufacturers will either list the total weight of grains on a bolt or list a grains per inch (GPI) value for the bolt. To calculate the total weight of a bolt from its GPI value, just multiply the GPI value by the length of the shaft. You can covert the weight from grains to grams simply by multiplying the total number by 0.0648.

D. Nock

A plastic or aluminum attachment that fits directly onto the back of the shaft. The nock serves the purpose of keeping the bolt in place while you line up to take a shot. Multiple varieties of nocks are available. The primary types are the half-moon nock or flat nock. Capture nocks, multi-groove nocks, and Omni nocks are other options. Different nocks carry different requirements. With a half-moon nock, for example, it has a groove you need to align with the bow’s string before firing a bolt.

E. Fletching

The vanes or wings at the back of a bolt. Arrow fletching is located in close proximity to the nock. It helps stabilize the bolt during flight. The fletching keeps the bolt from pitching or swaying in the air and keeps it going in the right direction toward the intended target. It causes the bolt to spin on its axis after it is released from the bow in order to increase stability. Bolts typically come pre-fletched with vanes molded from plastic and varying in length. Longer fletching is used with longer bolts.

F. Head

Crossbow bolts use two types of heads: field points and broadheads. Field points are ideal for target practice. They offer a pointy tip and no sharp edges. Field points aren’t recommended for hunting anything except some small game because they won’t strike with enough force and do enough damage to quickly kill larger prey. Most field points weigh from 125 to 150 grains and can be screwed into the front of the bolt shaft. Broadheads possess a sharp blade and are used for hunting. Crossbow shafts can utilize three different types of broadheads – fixed blade, removable blade, and expandable blade. Just like field points, they weigh from 125 to 150 grains. You can shoot regular compound bow broadheads, but you’ll get the very best performance with the specialized crossbow heads.

Time to Go Shoot!

One of the best parts of using a crossbow is learning how each component works. It helps you understand how to properly use it and care for it. Now that you know every inch of your crossbow from top to bottom, there’s only one thing left to do. Time to get it tuned up and get yourself ready to enjoy hunting season!