Crossbow Glossary – Popular Terms Explained

Welcome to our crossbow glossary. If you have questions about any of the terms explained below, please ask in the comments section at the bottom of the page and Mark, Lance or Jeff will get back to you with an answer as soon as possible.

LOP

“Length of Pull”. The distance between the butt of the crossbow and the middle of the trigger. This can greatly affect accuracy if too long or too short for a given shooter.

String Stops

Pieces of rubber placed on the crossbow such that they will provide a cushion for the bowstring as the crossbow is fired. These are designed to reduce vibration and to make the crossbow quieter.

Cam

On a compound crossbow, this is the semi-round “wheel” at the end of each limb of the crossbow. These are designed to allow greater power with less movement of the bow limbs to minimize dissipation loss of kinetic energy when the crossbow is fired. This should not be confused with the actual wheel found at one end of a compound bow.

Rail

The flat portion on top of the crossbow where the arrow is placed with the crossbow is loaded. This is very smooth as the string will glide across it as the arrow is fired. NOTE: This is different than a mounting rail or Picatinny rail.

Foot Stirrup

An extension off the end of the crossbow used as a brace to place the shooter’s foot in to assist in cocking.

Bullpup

A stock configuration that places the pistol grip and trigger further forward on the crossbow. This moves the center of gravity back towards the shooter’s shoulder and allows for less weight at the point of the forward grip, and therefore greater control.

Reticle

Most commonly called “crosshairs” in a scope, the reticle is made up of fine lines in the focal plane of a scope allowing for more precise aiming. There can also be graduations that assist in aiming more accurately at varying distances.

Illuminated Reticle

Typically either illuminated in red or green, this is where the reticle (also called crosshairs) is lit to assist in low-light shooting conditions.

FPS

“Feet per second”. This is the typical measurement of how fast an arrow is traveling when it leaves the muzzle. The faster the arrow travels the more energy it carries, all other variables remaining constant.

Draw Weight

The amount of force required to draw the limbs back and cock the crossbow. The draw weight, along with the powerstroke and arrow weight, is one of the largest factors for calculating a crossbow’s muzzle energy.

Muzzle Energy

The energy, typically listed as foot-pounds (ft. lbs.) that a projectile has as it leaves the muzzle of a weapon. In the case of a crossbow, it is the energy that an arrow has as it leaves the muzzle end of the rail of the crossbow.

Riser

The flat smoot portion of the crossbow where the arrow sits when cocked, and where the string glides along as the arrow is fired.

Stock

The portion of the crossbow that the shooter places against his or her shoulder when firing the crossbow.

Adjustable Stock

A stock that allows a shooter to change the length of pull (LOP) to more precisely match his or her arm length, and thus improve shooting stance and accuracy.

Foregrip

The forward part of the crossbow frame that allows the stabilizing hand of the shooter to grasp to improve control and accuracy.

Thumbhole

When the pistol grip is connected to the stock from the lowest point of the grip, a thumbhole is created. This can add stability for the firing hand.

Arrow

The projectile fired from a crossbow that has a point (field point or broadhead) and is stabilized by fletching or vanes. Many times the term “bolt” is used to describe a crossbow projectile, but a bolt does not have stabilizing vanes or fletching, while an arrow always does.

Bolt

The term for the projectile fired from a crossbow, many times used interchangeably with “arrow” for a crossbow. A true crossbow bolt does not have any type of fletching or vanes, while a crossbow arrow is typically just an arrow shortened to fit the crossbow’s shorter powerstroke.

Vanes

Often used interchangeably with the term “fletching”. In the truest definition, vanes are made from plastic (while fletching is made from feathers) and are mounted near the rear of an arrow to allow for stabilization in flight.

Fletching

Often call ‘vanes’ as well, these are mounted near the rear of an arrow to allow for stabilization in flight. In the truest definition, fletching is made from feathers, while vanes are made from plastic. This word can also be used as a verb to describe the act of placing feathers or vanes on the arrow shaft.

Broadhead, Fixed

This is a type of hunting tip for an arrow that has 2 – 4 razor blades attached to a central mounting point designed to create large wound channels (2” to 3” diameter). The blades are often removable such that they can be replaced with new blades to ensure maximum sharpness after each hunt. These are typically found in 100 – 150-grain weights.

Broadhead, Mechanical

This is a hunting tip for an arrow that resembles a field point (although it has razor blades hidden within the shaft of the head) and flies very similarly. Upon contact with an animal, the razor blades deploy to allow for larger wound channels (2” to 3” typically).

Field Point

A tip for an arrow that is typically used for practice. The tips are designed to allow someone to practice without tearing up targets and are much more economical than hunting broadheads. They are typically found in 100 – 150-grain weights to mimic the weight of a hunting broadhead.

Nocks

The rearmost portion of an arrow. This is the only part of the arrow that should ever come in contact with the bowstring, and is the part that receives the lion-share of the force imparted by the bowstring. Nocks usually are in one of two categories: flat and half moon.

Split Limb

A limb design on a crossbow where each limb is actually made of up two parts. This can reduce weight and also allow for the placement of dampeners to decrease sound and vibration when the crossbow is fired.

Trigger Pull

The amount of force required for the trigger to release. Generally, the lighter the trigger pull, the more accurate the crossbow will be.

Anti Dry Fire

A system that will not allow a crossbow to be fired unless an arrow is in place on the rail. This can help prevent significant damage to the limbs of the crossbow.

Dry Fire

The firing of a crossbow when no arrow is on the rail. This can lead to significant damage to the limbs of the crossbow. Many modern crossbows employ a safety that will not allow the crossbow to be fired without an arrow in place.

Compound

A type of crossbow that uses cams and pulleys to increase the force that the limbs apply to an arrow. The compound crossbow is generally more powerful than the recurve crossbow, but can sometimes suffer more issues due to more moving parts.

Recurve

A type of crossbow that has the string attached directly to the ends of the limbs. The recurve is generally not as powerful as a compound crossbow, but is preferred by many due to the more simple nature of its construction. Less moving parts can sometimes mean greater reliability.

Picatinny Rail

A mil-spec (military specification) based on MIL-STD-1913. This is a mounting system, typically along the foregrip or on the scope-mounting rail, to allow for the mounting of accessories, including a vertical foregrip, lights, laser sights, etc. Many Weaver mounts will fit the Picatinny rail, but Picatinny mounts will not fit Weaver rails due to the sizing of the recoil grooves.

Pistol Grip

The grip just behind the trigger that is grasped by the firing hand of the shooter, making the crossbow more ergonomic.

Vertical Foregrip

Typically mounted to a picatinny rail on the foregrip, this is a vertical grip used by the non-firing hand to make the crossbow more ergonomic when held in the firing position.

Quiver

Anything used to hold and carry arrows with a shooter when not in use. This is typically a system that is mounted (and often detachable) to the crossbow to securely carry arrows and protect the broadheads (and the shooter).

Bore Sighted (Scope)

When a scope is mounted to a crossbow and initially sighted down the bore of the crossbow. This will typically get the first arrows ‘on paper’ and allow for quicker sighting in of the crossbow.

Weaver Rail

A mounting system similar to the Picatinny Rail, but with a narrower recoil groove. This is typically used to mount scopes on the scope rail. A Weaver mount will typically fit the Picatinny Rail, but a Picatinny mount will not fit the Weaver rail.

Scope Rings

The metal rings that allow the mounting of a scope to a rail system. The rings clasp the tube of the scope and clamp it into an immovable position.

Scope #’s (i.e. 4×32)

The initial number in the X x XX is the magnification power of the scope. The second is the aperture size, listed in millimeters (mm). The higher the magnification, the better the long range accuracy will be. The higher the aperture size, the better the scope will gather light, which will mean better visibility in low light conditions. There is also a variable power scope, where the magnification is adjustable. These scopes will typically list the numbers as 3-9 x 32, showing the magnification is adjustable from 3 power to 9 power, and the aperture is 32 mm.

Suppressors

Rubber pieces added to either the limbs and/or the string of a crossbow to quiet the crossbow during firing.

Hand Guard

A “shelf” or other protrusion along the rail of a crossbow that is designed to keep the forward hand/thumbs/fingers from coming in to contact with the string when the crossbow is fired.

Automatic Safety

A system that automatically sets itself when the crossbow is cocked to ensures that the weapon cannot be fired, even if the trigger is pulled.

Skeleton Design

A design of a crossbow stock that eliminates the material from the center of the stock/foregrip to allow for the same outside dimensions of the stock/foregrip, but lowers the overall weight of the crossbow.

Powerstroke

The distance the string travels from the fully cocked position to the uncocked position when the crossbow is fired. A longer powerstroke will often mean increased speed, all other variables remaining constant.

Rope Cocker

A cocking aid that hooks to the string of the crossbow that will typically decrease the force necessary to cock a crossbow by approximately 50%. Most crossbows are compatible with a rope-cocking device.

Crank Cocker

A system that mounts on a crossbow stock that allows the user to simply turn a crank to cock a crossbow. This is considered the easiest method in which to cock a crossbow in terms of strength required. Not all crossbows are compatible with a crank-cocking mechanism.

Arrow Weight (Grains)

The weight of an arrow. Equal approximately 64.8 mg, the grain is the standard unit by which to measure arrows. Typical arrows for a crossbow will weigh from 200 – 400 grains. Careful attention must be placed to ensure when measuring the weight of the arrow that consideration is taken as to whether that includes the broadhead or field point as well.