Rifle Scopes 101: Parts

Here at Outdoor adventure group we take up any hobby from rafting to hunting. Today we are going to be discussing everything you need to know about the hunting rifle scope. The rifle scope is the most important component of the rifle, this is simply because you need to be able to see your prey from a distance.

Before you shop around for rifle scopes, it is a very good idea to understand how this item is assembled and how it works. Here we will talk about parts of a rifle scope. Let’s begin.


Eye Piece

The eyepiece is the metal chassis that holds the ocular lens. It is attached to the eye bell. You can find the eyepiece at the back of the scope

Eye Bell

It is the housing that is attached to the eyepiece.

Ocular Lens

The ocular lens is the lens that is located closest to the eye.

Eye Relief

This term refers to the distance from the eye to the ocular lens when one sees the full field of view. The higher the eye relief, the less the risk of being hit in the eye by the scope when the rifle recoils.

Power Ring

It is a part that is used to adjust the magnification on a scope with variable magnification. Turning the knob will change the distance between the internal lenses and the objective lens. It adjusts the amount of light going through the scope as well.

Objective Lens

It is the bigger lens located on the outside front of a scope. Its diameter regulates how much light enters the scope. Scopes that have higher magnification factors will need larger objective lenses. The same principle applies to scopes that are used in condition with dim lighting. For instance, dusk or dawn.

Some variable scopes have adjustable objective lenses that can be used to correct the apparent variation in the position of the target (the parallax error) created by their design.

Windage Adjustment

The windage adjustment moves the aiming point along the horizontal plane in order to sight the scope. The distance that the aiming point moves is generally measured as Minute of Angle or MOA. Each click of the knobs adjusts the aim point when the target is set at 100 yards distance.


Elevation Adjustment

It is similar to the windage adjustment. But, instead of moving the aim point along the vertical plane.


The tube is the body of the scope. As a matter of fact, a scope is basically a tube contained inside a tube. The inner tube contains the lenses used to refract light in order to magnify objects. The outer tube protects the inner tube as well as other components while providing a solid mount for the eyepiece and objective bell.

Tube Diameter

In general, American scopes have a one-inch diameter. And scopes made elsewhere have a 30 mm diameter. The rings that are used to hold the scope to the rifle mount are sized based on the tube diameter.

A 30 mm scope may be stronger and more adjustable on the horizontal and vertical planes. However, it comes at the cost of being heavier due to its extra components. It is a better option for long range shooting and higher magnifications. A one-inch scope, on the other hand, is enough for all other uses.

Objective Bell

It is the housing attached to the tube which holds the objective lens. Located on the front of the scope.

Knowing your rifle scope is a Important part of becoming a successful hunter. Once you know what to look out for you can go ahead and successfully purchase your first rifle scope. Remember, failing to prepare is preparing to fail.

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