Understanding The Instrument: A Quick Scope Overview
Objective Lens
At the front end of the scope, you’ll find the objective lens. This is the larger lens that gathers light from the target and begins the magnification process. The diameter of this lens is a crucial piece of information, as you’ll soon discover.
Eyepiece
Peering through the rear of the scope, you look through the eyepiece. This lens system focuses the magnified image for your eye. It also allows for adjustments to accommodate your individual eyesight, helping you achieve a clear, sharp view of the target.
Turrets
Moving to the top and/or side of the scope, you’ll find the turrets. These are the dials you use to adjust your point of impact, correcting for factors like distance, wind, and other variables. The numbers on these turrets also play a critical role in precise aiming.
Reticle
Inside the scope, you’ll find the reticle. The reticle is the aiming point, often taking the form of crosshairs, dots, or more complex patterns. This reticle will be the central element you use to line up your shot on the target.
Focus Adjustment
Finally, many scopes feature a focus adjustment. This allows you to sharpen the image by adjusting the focus to the target distance, ensuring clarity.
Deciphering Magnification and Lens Diameter
Now, let’s get to the heart of the matter: the numbers. The most prominent set of numbers on your scope typically involves a multiplication symbol, something like “3-9×40” or “6-24×50”. This combination reveals the magnification range and the size of the objective lens.
The first number you encounter often indicates the minimum magnification power of the scope. For example, in a “3-9×40” scope, the minimum magnification is three times. This means objects will appear three times closer than they would to the naked eye. At this magnification, the scope provides a wide field of view, making it easier to acquire targets at close ranges.
The second number, separated from the first by a dash, represents the maximum magnification. Continuing with the “3-9×40” example, the scope can magnify objects up to nine times. This allows for detailed observation of the target, making it ideal for long-range shooting or precise target identification. Many scopes offer a variable magnification, meaning you can adjust between the minimum and maximum settings.
The “x” symbol between the numbers signifies “times,” indicating the magnification power. So, “9x” means “nine times magnification.”
Following the “x,” you’ll encounter another number. This number provides information about the objective lens diameter, which directly affects how much light the scope gathers. This number is measured in millimeters. A scope marked “3-9×40” has a 40mm objective lens. This means the lens is forty millimeters wide. A larger objective lens gathers more light, resulting in a brighter and clearer image, especially in low-light conditions. However, a larger objective lens can also increase the scope’s overall size and weight. The larger objective lens does give you a brighter view, especially when the available light is low, but the trade-off is usually a heavier scope and/or a higher mounting position.
Important Considerations: Beyond the Primary Numbers
Understanding these primary numbers is essential, but other factors greatly influence scope performance and your shooting experience.
Field of View (FOV)
Field of View (FOV) refers to the width of the scene you can see through the scope at a given distance. This is crucial for target acquisition and tracking moving targets. As magnification increases, the field of view generally decreases. A scope with a wider FOV at a lower magnification is typically better for close-range shooting and quicker target acquisition.
Eye Relief
Eye Relief is the distance your eye needs to be from the eyepiece to see the full field of view. Adequate eye relief is crucial for safe and comfortable shooting. Too little eye relief can lead to recoil-induced injury, especially with powerful firearms. A longer eye relief also helps you to see the target easily.
Tube Diameter
Tube Diameter is the measurement of the scope’s main tube. Common tube diameters include one inch (25.4mm) and thirty millimeters. This diameter affects the internal adjustment range of the scope (the range you can adjust the elevation and windage turrets) and also influences the type of rings (mounts) required for attaching the scope to your firearm.
Turret Deciphering: Adjusting for Accuracy
The numbers on your turrets are critical for making precise adjustments to your point of impact. They typically represent either Minutes of Angle (MOA) or Milliradians (MRAD).
Minutes of Angle (MOA)
Minutes of Angle (MOA) is an angular measurement. One MOA is approximately equal to one inch at a hundred yards. Knowing this, you can adjust your turrets accordingly to account for wind drift, bullet drop, and other environmental factors. When dialing in MOA, each click on the turret often represents ¼ MOA, meaning that with each click, your point of impact will shift by ¼ of an inch at one hundred yards.
Milliradians (MRAD)
Milliradians (MRAD), or milliradians, is another system for angular measurement, often used in military and some competitive shooting circles. One MRAD is equal to 10 centimeters (approximately 3.6 inches) at one hundred meters. MRAD turrets usually have clicks representing 0.1 MRAD.
Each scope will define the value of each click on the turrets, and by understanding this information, you can adjust for the distances and environmental conditions.
Click values can be important to understand. It’s common for scopes to have clicks representing ¼ MOA or 0.1 MRAD adjustments. This is the amount the point of impact will move on the target for each click.
Reticle Markings: Aligning Your Shot
The reticle, those crosshairs or aiming points, is the focal point of your aiming process. Reticle markings, like the graduations on an MOA or MRAD reticle, are designed to help you compensate for bullet drop and wind drift, especially at longer ranges.
Many scopes use various reticle types, each with its unique set of markings. Mil-Dot reticles, for instance, feature a series of dots, spaced apart in Mil increments. These can be used to estimate range, allowing you to choose the appropriate aiming point to compensate for bullet drop.
Zeroing the scope
Zeroing your scope is the process of aligning the reticle with your rifle’s point of impact at a specific distance. This involves firing a group of shots, observing where they land, and then using the turrets to adjust the reticle until the point of impact matches the point of aim. Once properly zeroed, you can then use the reticle markings and turret adjustments to compensate for bullet drop and wind drift at different ranges.
Choosing the Right Scope Numbers: Context Matters
The ideal scope numbers for you will depend entirely on your intended use. The range you will shoot, the targets, and the environmental conditions play key roles in making the selection.
For hunting at shorter ranges, a scope with lower magnification, such as 1-4x or 2-7x, might be ideal. This provides a wide field of view for quick target acquisition. Larger objective lenses are beneficial in low light conditions.
For long-range target shooting or hunting, a scope with a higher magnification range, such as 6-24x or even higher, is generally preferred. This allows for precise aiming at distance.
For tactical applications, scopes with illuminated reticles and MOA or MRAD turrets are often used.
Conclusion: Mastering the Scope – Precision in Every Shot
Understanding the meaning behind the numbers on a scope is fundamental to achieving precision and accuracy. It’s about much more than just putting crosshairs on a target; it’s about mastering the tools that allow you to compensate for the variables, the wind, the range, and the trajectory, that influence your shots. Now that you’ve explored the fundamentals of scope markings, you’re better equipped to make informed decisions when selecting a scope, and to effectively use one in the field. Remember, practice is key. Spend time familiarizing yourself with your scope, learning how the turrets and reticle interact, and practicing at various distances to develop your skills. The more familiar you become with your equipment, the more confident and accurate you will be.
