How Does a Rifle Scope Work?

Just bought a rifle for hunting? But don’t know how to use the rifle scope? Then worry not! This article will give a basic breakdown of how the rifle scope works and the instruments inside the rifle scope.

Whats Inside of a Rifle Scope?

Before diving into how the rifle scope works, you have to know what is inside a rifle scope. Let’s know about them below:

Scope Lenses

A rifle scope contains up to eight separate lenses. At a minimum, the rifle scopes have the following:

• Objective Lens

When you hold a rifle, one end you look at is the eyepiece, and the other part of  glass is the objective lens. The objective lens is positioned fully forward in the scope tube of the rifle.

• Erector Lens

It is located inside the main scope tube. It is a mechanical system that creates magnification and controls points of impact.

• Magnifying Lens

This lens helps to magnify the object making it appear closer and larger. It makes a proper orientation of the image.

• Ocular Lens

The ocular lens is the glass through which the shooter sees and aims at a target. It is smaller than the objective lens. It gathers light through the objective lens and passes it to the other end, that is, the ocular lens, into the eyes of the shooter.

Scope Magnification

It may surprise you that a rifle scope works the same way as a telescope. First, the light passes through the objective lens and meets at the focal point. The bigger the objective lens, the more light will enter, making the image brighter and in high contrast.

Since the image is inverted now, taking an accurate picture would be quite challenging without an erector lens. It makes a proper orientation through the erector lens. After that, it passes to the magnification lens to increase and decrease the image's size.

For example, take a look at the 3-9*40mm scope. 

The 3 means three times closer compared to viewing.

The 9 determines how much closer the target will appear to increase magnification.

The 40mm is the diameter of the lens. This type of rifle sets the magnifying lens in a fixed position.

Then, the image is passed to the ocular lens, and the shooter can see the image the way he wants. 

First Focal Plane and Second Focal Plane

Knowing about the first focal plane (FFP) and the second focal plane (SEP) is essential. An FFP scope has a reticle placed in front of the magnification lens. Thus, objects change when the magnification goes up and down.

On the other hand, the reticle of SEP is placed behind the magnification lens. So, the objects remain the same. The SEP scope works well if you are looking for the highest magnification. FFP scopes allowed for long-range hunting. 

Besides, there is a power ring on the rifle scope to adjust magnification up and down. The magnification level is ranged from 2x up to 25x and beyond. 

A 25x magnification means 25 the object is 25 times closer to the human eye. You should look for the eye assembly and its coating to get the best rifle scope. Advanced coating technologies are developed by brands like Nikon, Leupold, and Zeiss.

Types of Reticles

When you look through the ocular lens, there is a crosshair through which you will look at the object. It is known as a reticle. The reticle comes in different styles and designs with specific purposes.

You will find nine reticles available for a rifle scope as follows:

• Original - It is a single vertical and has a horizontal crosshair.
• Dot- It has a single dot in an enclosed circle.
• German reticle-  In the center, the crosshair is tapered. 
• Duplex- There are thick crosshairs with a weakened center
• BDC- It is known as Bullet Drop Compensation
• Mil-DOT- There is a ballistic reticle that is measured in milliradians 
• Non-illuminated - This is simple and black
• Illuminated- It makes the object more illuminated
• Christmas Tree - The reticle is shaped like a tree.

Reticles have become advanced as optics. Hunting communities now prefer modern glass-etched reticles because of their durability. Some reticles have a simple three-post design, while others have calibrated designs and MIL-DOT specifications.

The best reticle for your purposes will depend on the hunting you plan and many other factors, including personal preferences and environmental factors. 

The object's size will remain the same if the reticle is placed in front of the magnifying lens. At the same time, the object's size will remain unchanged if the reticle is placed behind the magnifying lens. 

Scope Adjustments of the Rifle

Properly adjusting the rifles is key to focusing and having a good target. On top of the rifle scope are two knobs to adjust the scope for windage and elevation. 

There are four adjustments as shown below:

• Elevation Knob

The elevation knob allows the shooter to adjust the vertical position when the bullet is fired. Turn the turret counterclockwise to move the direction up if the bullet's point of impact is low. The opposite is true if your bullet impact is high off the target. 

The knob has markings for adjustment. These markings are measured in MOA (minute of angle). MOA is the unit of angular measurement. Each click on the knob is ¼ MOA which can change the position of the point of impact. 

• Windage Knob

The Windage knob changes the adjustment of the bullet impact left or right. Windage changes are rarely a problem at distances of up to 60 yards.

However, wind gusts can change a projectile's trajectory if you are sighting in at 200, 300, or more yards. Another tip is always to adjust the windage and then adjust the elevation.

• Parallax

The parallax knob aims to set the focal plane of the reticle to see an optical illusion. The reticle causes the target image to appear in 3D. The target image appears to be painted on if there is no parallax.

• Magnification

There is a ring forward on the ocular lens to adjust the magnification. Some scopes adjust the entire ocular lens assembly. 

Conclusion

In summary, a rifle scope is a precise instrument for greater accuracy for a shooter to aim at a target object. Any shooter who wants to improve their accuracy should understand the proper use of a rifle scope. Thus, a rifle scope can be a valuable tool for shooters with the right training and practice.