The Rifle Scope: Everything You Need to Know 

 August 27, 2020

By  Jacqui Cheng

Did you know that before the Civil War, the main purpose of telescopic scopes was hunting and shooting? However, the overall design and functionality of the scope underwent significant advancements right after World War II.

This development sparked the era of the modern rifle scope. Manufacturers produced cutting-edge scope designs to help hunters aim better than previous scopes. The scopes are the benchmark of telescopic and dot sights you see mounted on assault rifles today.

Purpose Of A Rifle Scope

The primary purpose of a rifle scope is to magnify and significantly enhance your target. It helps you get a crystal clear picture of the target compared to the naked eye. A good scope not only enables you to put some accurate shots on target, but you will also be able to shoot your target from ridiculously long distances.


Plus, good scopes also increase your safety while shooting – you will always be able to see what lies behind the target so that you can shoot carefully and avoid shooting anything else other than the target.

But perhaps the best advantage of quality, a cutting-edge scope is the fact it will always allow you to hunt early in the day or when the sun begins to make its descent into the horizon.

When you talk about hunting big game like a deer, elk or hog, it is important to understand that these animals move from their bedding areas and coming back to their dens and whatnot.

But that could be anytime during the day or night, which is why iron sights just don't cut it anymore. There is no way you will be able to see the target in low light conditions properly. And when it's bright, you won't be able to aim for a long distance without disturbing the animal.

Riflescopes are designed to accentuate ambient light – which means they can enhance the surrounding light no matter how little in quantity. You can take a more ethical shot with a modern scope compared to iron sights.


Quality scopes with multi-functionalities enable a superior level of accuracy and precision compared to iron sights. For example, if you're taking a shot from a distance of 100 yards, using iron sight will only give you target coverage of 6 inches. Placing a precise bullet into the target will be drastically limited by the size of the target covered.


However, different scopes come with varieties of different types of reticles that give you 1/8-inch of cover at a distance of 100 yards. This target coverage is exact – giving you ample time and opportunity to place a clean, one hit one kill shot. Using a scope and some patience, you can even put a shot on the same hole as your first shot.

Reading Rifle Scopes

Reading the numbers printed on the scope is one of the most basic aspects of the rifle scope. The numbers are in a general format with the amount of magnification printed first, and the diameter of the objective lens is second.

The number defining the magnification represents the extent of the magnification when you look at the target through the scope.

There is often just two number printed for the magnification of the lens – a dash will always separate the numbers. The dash indicated the fact that you can easily adjust the magnification of the scope back and forth based on the distance of the target. You can adjust the magnification from a low number to the highest number.

Let’s take an example of a scope with a 3-9x40mm - the first number on the rifle scope represents the lowest amount of magnification. The second number defines the highest. The dash indicates that you can adjust your magnification from high to low or from low to high.

So, you can adjust the scope from a 3x setting for magnification to a 9x setting and anywhere in-between – like 3.5 or 6.5. The last number, 40mm, represents the diameter of the objective lens – which is the forward-most lens. You will find this number listed in millimeters.

How Do Rifle Scopes Function – An In-Depth Look At The Anatomy Of Modern Scopes

In its purest form, modern rifle or hunting scopes are just tubes that are designed to house power lenses for effective magnification. Housed inside the scope are reticles or crosshairs that you use to aim. The crosshairs help show you whether or not the bullets are going to land on the target and it also indicates the total impact of the shot.


The main frame of the scope’s tube comes in either one-piece or two-piece construction. These tubes are manufactured using commercial-grade aluminum. This type of aluminum is aircraft aluminum. However, there are rifle scopes that are manufactured using steel and titanium.

But regarding weight and cost, it is better that you opt for a scope made from aluminum. With steel, you would have to constantly keep it clean and maintained because the material rusts quickly and easily if you neglect it.

Components Outside The Scope

The scope that is far away from your eye is the objective bell. This component also contains the objective lens. The objective bell is designed to capture ambient light effectively – the amount of light that the object captures is directly proportional to the diameter of the objective lens.

The bigger the diameter, the more light it will capture, allowing you to see better in bad or low light conditions. The end through which you look into the scope is an ocular piece or an eyepiece.


Apart from keeping the internal components of the tube safe and damage-free, the external scope has the surface area required to adequately and safely mount it on the rifle.

Plus, the external part of the scope features tiny knobs you will use to adjust the scope and magnification. You can fine-tune the scope for sheer performance and efficiency.

At the midpoint of the external scope, there are knobs so that you can easily adjust the elevation and windage of the rifle.

Setting the windage will enable you to properly adjust the crosshairs or reticle of the rifle to control the impact of the bullet from left to right of the range. The elevation correction knob helps adjust the right point of bullet impact up and down the scope.

As soon as you turn the knobs for aim adjustment, you will hear a clicking noise that will indicate the level of the adjustment. Riflescopes come with two click values, which are 0.1 (MRAD) short for milliradians and ¼ (MOA) short for Minute of Angle.

However, there are rifle scopes that come with an additional knob – which helps adjust the parallax of the scope. You can adjust scopes that do not have a parallax knob by rotating the far end of the scope – the objective bell.

These types of scopes are known as Adjustable Objective or AO rifle scopes. The scopes feature a diopter adjustment mechanism that helps properly adjust the reticle of the scope by carefully rotating the eyepiece.

It is a common mistake to aim at the target by adjusting the diopter of the scope in the eyepiece. In actuality, all this does is adjust the focus of the crosshair and not your prey.

Components Inside The Rifle Scope

The anatomy of the internal scope is a bit more complex, but it is worth knowing. Remember the most important part of the scope is the lenses you see and aim through. Front to back – the scope is fitted with an objective lens as well as a focus lens, then you have magnification lenses and the eye-piece.


Modern rifles come fitted with scopes that a pre-coated with anti-glare and to keep reflection to a bare minimum. Minimal reflection enhances the amount of light transmitted through the objective lens and right in your eyepiece.

There is a tiny tube inside the scope that houses the objective lens mechanism and assembly. If the scope is designed to be AO, you can easily adjust the parallax of the scope via the rotating mechanism inside the objective lens.

The focus lens is at the back of the objective lens. You can either fix the focus of the scope or adjusted from time to time. Fixed focus lens scopes are by default designed to be parallax-free at certain ranges, for example, 100 meters or 100 yards.

Continuing to move back to the internal mechanism of the scope we will find something known as the erector tube. This component contains the assembly for both reticle focus and lenses for magnification. In power scopes, the magnification lenses change their positions inside the erector tube when the power ring rotates.

Types Of Rifle Scopes You Can Opt For

Many people mistake the scope of the rifle for a gun sight. The major difference between gun sights and a proper scope is the fact that rifle scopes have magnification capabilities while iron sights or gun sights do not.

Make this a rule of thumb whenever you go out to shop for a quality scope. There are different types of scopes that you can choose.


However, you should select the scope as per your specifications and hunting requirements. In light of this, mentioned below are some of the most common scopes used:

  • Open Sights – These scopes require the person to line up more than one sight on the assault or hunting rifle to take a precision shot. Rear sights are designed with a U or V shape while the frontal sight is designed to have a vertical shape.
  • Aperture Sights – These are similar to open sight. However, aperture sights feature a ring that acts as a rear sight. You have to aim first.
  • Red Dot Sights – These are quite popular. The sights are designed to project a red dot on the target through the reticle of the scope. The red dot is illuminated to help you make a more precision-based shot. However, keep in mind that the dot doesn't come out of the end of the scope.
  • Laser Sights – These are similar to dot sights, but the scope projects laser beams on the target.
  • Night Vision – These scopes are important if you hunt at night and are attached with a night vision mechanism atop the lenses for clear and unhindered vision when you are hunting foxes and other nocturnal creatures.

Different Specifications Of A Rifle Scope

Read on and find out more about different specifications of a rifle scope:


Quite literally put there are a plethora of reticles you can opt for in a rifle scope. Each comes with different patterns – from traditional center dots to sophisticated patterns forming a grid, mentioned below are a handful of the most common and popular types of reticles used:

The Duplex Reticle

As far as popular and effective reticles go, duplex reticles popular among a majority of people throughout the world. A thin crosshair differentiates this type of reticle right in the center of the scope.


The reticle begins to appear thicker at the external part of the rifle scope. Whenever you imagine looking through a hunting scope or play the first-person shooter, the scope you are looking through has a duplex reticle.

It is a pretty neat design that automatically enables the eye to firmly focus on the target dead at the center of the scope without being distracted. The part that gets thicker on the outside help corrects your vision in low light environments.

Mildot Reticles

These reticles are designed in the same patters as the duplex reticle. However, mildot reticles have pretty powerful enhancement features. The total size of the dot in the center and the dots throughout the reticle-lines correspond directly to particular angles, measured in MRAD or milliradians.

The real power of this reticle is the fact that you can use it to effectively identify the range of the target only if you have a good idea of what its size is. You can use the reticle for fast adjustments in aim and intuitive adjustments for long shots where you have to also adjust for the wind and elevation of the plane.

Bullet Drop Compensator Or BDC Reticles

BDC reticles have become quite common these days and for a good reason. These reticles enable you to make highly precise and accurate shots throughout a plethora of target ranges.


But the best part is you don't have to make any elevation adjustment. That is because the bullet drop compensator features multiple aiming points. You can find all this in the pattern of the reticle. The patterns effectively correspond to a variety of distances when you’re hunting.

Optical Power

Before buying a scope, the first thing you should consider is the type of magnification you require. The type of magnification it has will determine the limits of its performance when you're hunting. For example, if you're shooting at a target from a distance of 1000 yards, you will get nowhere with a scope that has a 4x magnification.

Similarly, if you're getting a scope for deer hunting, using a 32x rifle scope will result in zero accurate shots on target. You have to consider the range and the environment where you will use the scope.

The optical performance of a rifle scope is a matter of preference and hunting conditions. But it is imperative to remember that low magnification – like 4x or 6x magnification will enable you to shoot more intuitively and with speed. Not to mention, a scope with these specifications will also help you track the target with precision.


For accurate target resolution, you should go for rifle scopes that come with 16x magnification or higher. However, these scopes are quite pricey and not to mention heavy as well. So, they will do you no good if you’re going to be shooting from unsupported terrain or positions.

As a good rule of thumb, rifle scopes that feature a 10x magnification are more effective for shooting at offhand distance, which is distances less than 500 yards.

Scopes have more than 10x magnification is suited for hunting at greater distances from supportive angles and positions, for instance, placing the rifle on a sandbag or a bipod.

Minute Of Angle (MOA)

A unit of measurement printed on the scope for range and reticle adjustment – Minute of Angle technically refers to 1/60th of an angular degree. The unit is suitable for calculating linear inches, which is primarily due to the fact 1 Minute of Angle pretty closely equals to 1 inch while shooting at a distance of 100 yards.

The best thing about using the MOA adjustment is that it enables you to shoot with more precision and zeroing compared to scopes with milliradian units.

Milliradians (MRAD)

Milliradians, or mils or just simply mil, are clear representations of a fractional area of a given angle – it is 1/1000th of 1 radian. One MRAD roughly equals 3.6 inches when shooting at a target at the distance of 100 yards.


This measurement will sound a bit confusing at first, but when shooting with a MRAD scope, you will notice how simple it is to make target range adjustments compared to MOA scopes. Usually, people use MRAD scopes as a ruler.

In simpler words, if you have made a shot that indicates that the bullet has made an impact on the target falling 1.2 milliradians below the crosshair in the center, you will be able to quickly adjust the reticle, moving the know 1.2 MRAD on the top.

The best part about MRAD scopes is that making target adjustment in the scope is very easy and does not change no matter the range and distance of the target.

Focal Plane

The focal plane is an additional component that modern rifle scopes feature. This option enables you to set the reticle to one of the two positions of the crosshairs inside the scope. The two different positions are FFP, short for First Focal Plan and SFP, short for Second Focal Plane.

A lot of cutting-edge hunting and assault rifle scopes come integrated with the Second Focal Plane crosshairs, which essentially means that whenever you change the magnification of the scope, there will never be a difference in size of the reticle in conjunction with the range and size of the target.

This feature ensures your sights are clear and gives a more pristine magnification of the target.

Eye Relief

The eye relief when aiming from a scope refers to the safe and adequate distance you should keep your aiming eye from the scope. This way you will be able to maintain a bigger image of the pretty instead of sticking the scope to your eye and searching for areas on the target to hit.


Maintaining Your Rifle Scope

Scopes made from aluminum are easy to clean and maintain. Plus, all rifle scopes come fitted with covers that you can click back on when you aren't using the scope.

You can keep the lens clean all the time. Moreover, to clean the external part of the scope, just use a damp cloth to wipe all the dust and lint away. Do not use any detergent and make sure the water does not seep inside the internal tube.

Bottom Line

All in all, rifle scopes can help enhance your shooting abilities in a limited amount of time leading to faster and more effective shooting. Plus, just imagine how many rounds you will be saving using cutting-edge scopes. However, one cannot overemphasize the importance a quality rifle scope.

Jacqui Cheng

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