If you’re new to riflescopes, the numbers on them can look like a secret code. Understanding what does the numbers on a rifle scope mean is the first step to using your optic effectively. It’s simpler than it looks, and this guide will break it all down for you in plain language.
Those numbers tell you two main things: the magnification power and the size of the objective lens. They are the key to knowing how close your target will appear and how much light the scope can gather for a clear image. Let’s get started.
What Does The Numbers On A Rifle Scope Mean
The most common numbers you’ll see are formatted like “3-9×40” or “4-16×50.” This is the scope’s model designation, and it holds all the basic information. The numbers before the “x” refer to magnification. The number after the “x” refers to the diameter of the objective lens in millimeters.
Breaking Down the Magnification Number
The first part, like the “3-9” in 3-9×40, tells you the scope’s zoom range. It is a variable-power scope.
- The first number (3) is the lowest magnification. At 3x, your target appears three times closer than it does with your naked eye. This gives you a wide field of view, perfect for scanning or shooting at close ranges.
- The second number (9) is the highest magnification. At 9x, your target appears nine times closer. This is better for precise shots at longer distances, but your field of view becomes narrower.
- You can adjust the magnification anywhere between these two numbers using the magnification ring on the scope.
Some scopes have a single number, like “4×32.” This is a fixed-power scope. It has only one magnification level (4x in this case) and no adjustment. They are simple and reliable, often used for specific types of shooting.
Understanding the Objective Lens Size
The last number, like the “40” in 3-9×40, is the diameter of the objective lens in millimeters. This is the lens at the very front of the scope, farthest from your eye.
- A larger objective lens (e.g., 50mm) can collect more light. This generally means a brighter and clearer sight picture, especially in low-light conditions like dawn or dusk.
- However, a larger lens makes the scope bigger, heavier, and often requires higher mounting rings to clear the rifle barrel.
- A smaller objective lens (e.g., 28mm) keeps the scope more compact and lightweight, and it can sit lower on the rifle.
You need to balance light-gathering needs with the size and weight you’re willing to carry.
Other Important Numbers and Markings
Scopes often have other numbers etched or printed on them. These provide additional critical information.
Reticle Adjustment Numbers
On the adjustment turrets (the knobs on the top and side), you’ll see numbers like “1/4 MOA” or “0.1 MRAD.” This is the most important spec after the main model numbers.
- This number tells you how much the point of impact moves per click of the knob.
- “1/4 MOA” means each click moves the impact 1/4 Minute of Angle at 100 yards. Roughly, that’s a quarter-inch at 100 yards.
- “0.1 MRAD” means each click moves the impact 0.1 milliradians, which is about 0.36 inches at 100 yards.
- These numbers are essential for sighting in your rifle and making adjustments for wind or distance.
Field of View Specification
Sometimes the box or tube will list a field of view, like “42 ft @ 100 yds.” This tells you how wide an area you can see through the scope at a specific distance. A wider field of view makes it easier to track moving targets or scan an area quickly. This number gets smaller as you increase magnification.
Eye Relief Measurement
Eye relief is the distance your eye must be from the rear lens to see the full sight picture. It’s crucial for safety, especially on high-recoil rifles. A marking like “3.5 in” ensures you mount the scope correctly to avoid getting hit by it during recoil. Longer eye relief is generally safer and more forgiving.
How to Choose Based on Your Needs
Now that you know what the numbers mean, how do you pick the right one? It depends on what you’ll be using the rifle for.
- General Hunting & Woodland Use: A 2-7×32, 3-9×40, or 1-8×24 are excellent, versatile choices. The lower magnifications are great for quick shots in thick cover, while you have enough zoom for longer shots in a clearing.
- Long-Range or Varmint Shooting: Look for higher magnification ranges like 4-16×50, 6-24×50, or 5-25×56. The larger objective lens helps with clarity at distance, assuming the optical quality is good.
- Close-Quarters or Brush Guns: Consider a low-power variable optic (LPVO) like 1-4×24 or 1-6×24, or even a red dot sight. The 1x setting acts like a non-magnified sight for very fast target acquisition.
- Precision Target Shooting: High, fixed magnification scopes (e.g., 10×40, 20×50) or high-end variables with large objective lenses are common. The priority is a clear, precise image and reliable, repeatable adjustments (those turret numbers matter most here).
Remember, higher magnification also amplifies shaky hands and mirage (heat haze). There is such a thing as too much magnification for a given situation.
Putting It All Together: A Practical Example
Let’s say you have a scopes marked “3-12×44 SF FFP – 1/4 MOA.” Here’s what that tells you:
- 3-12x: Variable magnification from 3x to 12x.
- 44: A 44mm objective lens.
- SF: Likely means Side Focus, a parallax adjustment knob on the side.
- FFP: First Focal Plane reticle. The reticle size changes with magnification, so holdover marks are accurate at any zoom level.
- 1/4 MOA: Each click on the adjustment turrets moves the point of impact 1/4 Minute of Angle.
This would be a versatile scope suitable for hunting at various ranges or for tactical use, with features that aid precise shooting.
Common Mistakes to Avoid
When first learning about scopes, a few errors are easy to make.
- Thinking bigger magnification is always better. It’s not. It can make finding a target harder at closer ranges.
- Ignoring eye relief and mounting the scope too far forward or back, leading to a poor sight picture or a safety hazard.
- Forgetting that a huge 56mm objective lens will require very high mounting rings, which can make getting a good cheek weld on the stock difficult.
- Assuming all scopes with similar numbers perform the same. Optical glass quality, coatings, and construction make a massive difference in clarity, brightness, and durability. The numbers are just the starting point.
FAQ Section
What does 4×32 mean on a rifle scope?
It means a fixed 4x magnification and a 32mm diameter objective lens. It’s a simple, common setup for .22 rifles or shotguns.
Is a 3-9×40 scope good for deer hunting?
Yes, a 3-9×40 is arguably the most popular and effective scope for deer hunting in most environments. It offers a great balance of wide view and sufficient zoom.
What does 1/4 MOA at 100 yards mean?
It means that when you adjust the turret one “click,” the bullet’s point of impact on the target will shift by approximately 1/4 of an inch at a distance of 100 yards. At 200 yards, that same click moves it about 1/2 inch.
What’s better, a 50mm or 40mm objective lens?
A 50mm lens gathers more light, which can be benificial in low light. However, it’s heavier and needs higher mounts. A 40mm is more than adequate for most daytime hunting and offers a more compact profile. Choose based on when and where you shoot most.
Understanding these numbers takes the confusion out of choosing and using a riflescope. It allows you to select the right tool for your specific rifle and shooting needs. Next time you look at a scope, you’ll be able to instantly decode its specifications and know exactly what your getting. Now you can focus on the more important task: practicing your shooting skills.