ACCESSORIES

What is a rifle scope?

A rifle scope is an essential tool for any shooter, designed to clearly visualise targets at longer distances. Especially in hunting and precision shooting, a riflescope is indispensable, as it helps you aim accurately and hit your target. Choosing the right rifle scope depends on several factors such as magnification, size and the type of reticle.

How do you use a rifle scope?

A common question is how to look through a rifle scope. Keep the rifle scope a fistful of distance from your eye for a clear and full image. Experiment with the distance to get the optimum view without blurred edges. A properly adjusted rifle scope will ensure that your target comes into sharp and clear focus, which is essential for accurate shooting.

Types of rifle scopes

Scopes come with different types of crosses, such as the wire cross, MilDot and Circle Dot. Each type of cross offers unique advantages:

• Wire Cross: Ideal for accurate aiming at clearly marked targets.
• MilDot Cross: Provides accurate distance measurement and compensation for weather conditions.
• Circle Dot: Less common, but some shooters prefer this for specific targets.

Magnification and Eyepiece

The numbers on a rifle scope, such as 4x40, indicate the magnification and diameter of the objective lens. These features affect various aspects of your shooting experience:

• Magnification (e.g. 4x): The first value in the rifle scope's designation indicates the magnification. A 4x magnification means that the target appears four times larger than with the naked eye. Higher magnification offers more detail, which is useful for long-range shots. However, too high a magnification can also have drawbacks, such as a narrower field of view and more sensitivity to vibrations and movements of the weapon.

• Objective lens diameter (e.g. 40 mm): the second value in the designation indicates the diameter of the objective lens in millimetres. A larger objective lens captures more light, resulting in a brighter image, especially in low light. This is essential for hunting at dusk or in dense areas. However, bear in mind that larger objective lenses make the scope heavier and bulkier, which can affect the balance of your weapon.

Important Features of Magnification and Objective Lens

• Fixed versus Variable Magnification: rifle scopes can have either fixed or variable magnification. Fixed magnification means the magnification cannot be adjusted, which is simpler and often more robust. Variable magnification, such as 3-9x, allows the shooter to adjust the magnification to different shooting situations, which offers more flexibility but also adds more complexity.

• Field of view: The field of view (FOV) decreases as the magnification increases. This means that at higher magnifications, the visible area becomes smaller, making it more difficult to track moving targets. At low magnifications, the field of view is wider, which is beneficial for dynamic shooting situations.

• Light transmission: Larger objective lenses let in more light, which is important for brightness and image quality. This is crucial when shooting in low-light conditions. The quality of lens coatings also plays a big role in maximising light transmission and minimising reflections and glare.

• Exit pupil: The exit pupil is the diameter of light passing through the eyepiece lens and can be calculated by dividing the objective lens diameter by the magnification. A larger exit pupil means that more light reaches your eye, giving a brighter image. This is especially important when shooting in low light. Example: a 4x40 rifle scope has an exit pupil of 10 mm (40/4 = 10).

• Eye Relief: Eye relief is the distance between the eyepiece and your eye at which you can see the full image. This is important for preventing eye injury from recoil, especially with more powerful rifles. Scopes with long eye relief are safer and more comfortable to use.

IR and AO

• IR (Illuminated Reticle): Illuminates the reticle for better visibility in poor lighting conditions.
• AO (Adjustable Objective): Adjustable lens for focusing at different distances.

Mounting and Parallax

Mount your rifle scope as low as possible above the barrel with suitable mounting rings. Parallax refers to the apparent shift of a target when changing the viewing angle. More expensive riflescopes have adjustable parallax to minimise these errors. Setting the parallax correctly ensures a more accurate shot, especially at different distances.

Red Dot Scopes

A red dot system uses a red dot as an aiming scope, which simplifies aiming without magnifying the image. Red dots are ideal for situations where fast and accurate aiming is important, such as in tactical shooting scenarios and dynamic shooting sports.

The basics of riflescopes and how they work

Lenses in a riflescope

The main components of a rifle scope are the lenses: the objective lens, erector lens, magnifying lens and eyepiece lens. The objective lens is located at the front of the tube and collects light, which is then transferred to the erector lens that inverts the image. The magnifying lens magnifies the image, which is eventually viewed through the eyepiece lens, close to the user's eye.

Functioning of the Lenses

Light passes through the objective lens and is focused to a point within the scope, called the focal point. The image is then reversed by the erector lens and passed to the magnifying lens, which adjusts the magnification by moving towards the objective lens at increasing magnification, and towards the eyepiece lens at decreasing magnification. The eyepiece lens focuses the light and presents the image you see when looking through the rifle scope.

Eyepiece and Eye Relief

Eye relief is the distance between the shooter's eye and the eyepiece at which the full field of view is visible. Shorter eye relief means that the rifle scope should be mounted closer to the face, while longer eye relief, as in scout rifles, provides more space between the eyepiece and the eye, and can be mounted further forward on the weapon.

Water and Fog resistance

Most riflescope lenses are water- and fog-resistant, essential for various shooting conditions. Waterproof riflescopes are fitted with O-rings to keep out moisture and dust. To prevent condensation, the air inside the tube is replaced by gases such as nitrogen or argon, which do not contain moisture.

Magnification of the rifle scope

The magnification of the rifle scope indicates how often the image appears larger compared to the naked eye. Some riflescopes have fixed magnification, such as a 3x40 riflescope that magnifies the image three times. Other riflescopes have variable magnification, referred to as 3-9x40, meaning the user can adjust the magnification from three to nine times.

Reticles and Their Functions

The reticle, usually a cross-hair pattern, can consist of fine threads or be etched into a glass plate. Different types of reticles, such as duplex, cross-hairs, mil-dot, special purpose (SPR) and bullet drop compensator (BDC), are designed for specific applications or ammunition calibres.

Setting and Adjusting the Scope

Use windage (horizontal) and elevation (vertical) adjustments via knobs or turrets to zero the rifle scope so that the desired target is in the centre of the reticle. Reticles such as mil-dot and BDC have markings to make estimates of where shots land at different distances without resetting the rifle scope.

Mounting the rifle scope

When buying a rifle scope, it is important to know how to mount it on your gun and what size mounting rings are needed. Modern rifles often come with mounting bases such as a dovetail or a 1913 Picatinny rail. Mounting rings can consist of two separate parts or a single piece and must be correctly matched to the diameter of the rifle scope tube (1 inch or 30 millimetres).

Height of mounting rings

The height of mounting rings depends on several factors such as the cheek rest on the stock, eye relief, the diameter of the objective lens, the type of action and the lever of the lock. Lower rings place the scope closer to the rifle and require a lower position for good visibility, while higher rings allow more room for larger objective lenses and grips for lock actions.

Aligning the Reticle and Adjusting Eye Relief

The reticle of your rifle scope is the image you see on the lens that indicates where the weapon is aimed. It is usually a cross, but many variations are possible, such as circles and exes. With the mounting rings loose, rotate the scope until the reticle is properly aligned. Then adjust the distance from the lens to your eye to ensure it does not hit your eye on recoil.

Different Parts of the Scope

Although there are many manufacturers, almost all use the same basic parts: the housing, the eyepiece, the objective lens, the shoulder, and the knobs for windage, elevation and parallax. The shoulder of the rifle scope is where the diameter increases to hold the objective lens. The windage and elevation knobs move the reticle sideways and up and down, respectively. Parallax knobs are rarely adjusted and affect the movement of the reticle in relation to the target.

Using Single or Variable Magnification Lenses

A single lens offers one level of magnification, while a variable lens has a ring that allows you to choose between different levels of magnification. Most riflescopes are single lens, but if you have a variable lens, you can adjust the magnification with the ring between the shoulder and the objective lens.

Assessing Magnification Levels

You can determine the power of your rifle scope by looking at its model number. A rifle scope with the model number "4 x 30" means that the image appears four times larger through the scope than with the naked eye, and the objective lens has a diameter of 30 millimetres. Variable power models such as "4-12 x 32" mean the magnification can be adjusted between four and 12 times.

Eye Relief

Eye relief is the distance from the eyepiece to your eye at which you can see the full field of view. Higher magnification requires closer eye relief to see your target properly. Eye relief distances are often given as a range, such as 3-9x, meaning the correct eye relief is between 3 and 9 inches from the eyepiece.

Sight Picture

Without a rifle scope, a good sight picture involves aligning the rear and front sights. With a rifle scope, it involves centring the reticle in your field of view and positioning it over your target. Your sight image should form a perfectly centred circle with no black edges on one side.

Adjust based on the Impact of your Rounds

Be as consistent as possible when firing rounds at the target and assess where they impact. If you are consistent, the rounds should impact in the same area. Adjust windage to move the impact left or right and elevation to move the impact up or down.

Adjust Parallax

Some advanced rifle scopes let you adjust a third variable: parallax. Parallax is the movement of the target relative to the reticle when you move your eye. A problem with parallax can make the target and reticle appear to be on different optical planes. Adjust the parallax by moving your head while looking through the scope and adjusting the parallax knob until the reticle no longer appears to be moving.

Zeroing the Rifle

Once you understand how to adjust the scope, you can zero the rifle. This involves shooting at a known distance and adjusting the scope so that the reticle exactly matches the point of impact of the rounds. Use a bipod or shooting table to hold the weapon steady while you shoot to eliminate variables such as heartbeats, breathing and muscle fatigue.

Maintenance and Storage of the Scope

Protect the lenses of your rifle scope with lens covers when not in use. Use a lens brush to remove dirt or sediment and avoid cleaning the lenses with non-optical cloths. Use lens cleaning fluid and lens wipes to remove fingerprints or smudges. Store your rifle scope in a cool, dry place away from direct sunlight and extreme temperatures.