Does scope tube size matter? The short answer is yes, in some situations. However, longer scope tubes and wider ones don’t necessarily help. Let’s learn more about the relationship between scope tube dimensions and rifle scope performance.
When do larger tubes help you?
Larger tubes, those with a larger diameter, can house bigger movements for more elevation. This makes larger tubes useful if you’re doing long-range shooting. If you’re operating in low-light conditions, a larger tube can transmit more light simply because it has a larger lens.
Is bigger better when you need magnification?
When do larger tubes help you? One situation is when you need distance vision, such as when you’re going engaged in long-distance shooting. The larger the scope, the greater the objective diameter, the more light is collected.
We’ve already mentioned that this can help in low-light conditions, though lenses designed for that are better than just buying the biggest scope you can find. But if you’re using the scope as de facto binoculars, then a larger scope is generally going to give you better distance vision.
Furthermore, the larger scope comes with a larger lens, increasing the size of the “sweet spot” of the lens itself. This sweet spot is the area where the lens produces the sharpest, highest quality image. And it is much smaller than the scope lens itself.
Let’s use camera lenses as an example. The sharpest aperture for a camera is two to three stops smaller than the widest possible aperture for the camera. Why? Because the lens gets blurry near the edges. And the same is true of rifle scopes.
Why don’t rifles come with binocular scopes?
In theory, adding two sights instead of putting a large single-eyed sight on the gun would make sense. However, the ergonomics of shooting gets in the way. The first reason is that humans have stereoscopic vision but they have a dominant eye.
You want to look down the scope with your dominant eye, and trying to look through binoculars doesn’t improve anything. The second reason is that you want to be able to quickly line up the gun with what you’re seeing.
Binoculars actually throw that targeting off, unless you have built-in prisms to make up for it. That added complexity is unnecessary when you have the ability to just use a single scope. And a single eyepiece lined up symmetrically with the gun barrel lets you shoot once the target is lined up in the scope.
Furthermore, it is cheaper to simply use less hardware when it works, and single eye sights clearly work. Never mind the fact hunters and competitive shooters want a gun that is as light as possible.
How can I determine the magnification of a rifle scope?
If you’re researching gun scopes, you’ll see several numbers defining that scope. The first two numbers show the magnification of the lens and the power of the lens, if it is a variable scope.
Does a larger lens provide a larger field of vision?
In most cases, the answer is no. A 50 mm scope isn’t really going to give you a wider field of view or FOV than a 42 mm lens. The field of view for a 50mm lens may not be larger than that of a 42 mm lens.
But the image from a 50 mm scope will be brighter than that of the 42 mm lens, though this won’t make much of a difference in bright sunlight. In low light conditions, a 50 mm scope will let you use higher magnifications longer as the light diminishes.
Yes, you can increase the magnification to make up for reduced light in the right situations. Note that a larger scope won’t make up for a lack of light, so infrared cameras and night vision goggles may be a better choice for sighting prey if you’re hunting at night.
How does a larger scope affect the performance of the rifle?
Large scopes like 50 mm rifle scopes can only be mounted with a high mount. This can affect your eye alignment, increase the parallax and make it uncomfortable to use. This in turn can affect your accuracy.
In general, you’ll want a scope that has a low, consistent check weld. This is one reason why a 42 mm scope is considered better in most cases. It has a lower profile. And you can use standard medium high mounting rings with the scope.
Why do we say larger lenses generally improve visibility?
Many hunters look for larger lenses because they think it creates a brighter, clearer image. However, this isn’t true if the scope has inferior glass or the scope has problems with condensate fogging the lenses.
You can improve the performance of the scope by choosing one with high transmission glass and superior coatings. We recommend fully-coating scopes where all external glass is coated in a single layer.
The next level of lens coatings are multi-coating scopes. This is reserved more expensive scopes. Fully-multi-coating scopes have all external glass coating in several layers. This is rare unless you’re at the sniper level.
When do I want a wider riflescope?
A wider rifle scope allows you to see your target in lower light conditions like overcast weather. You can increase the magnification to make up for the decreasing light, whether it is becoming dark due to stormy weather or you’re entering an area with tree cover.
The smaller scope has less margin when you use this trick to improve visibility. But if you’re hunting at night, just get a night vision scope.
What are the downsides of a wider riflescope?
A wide scope tube size can hurt you. It doesn’t just increase the size and weight of the scope and thus the gun. It increases the odds of scope ring problems. And the sunlight reflecting off the objective lens can give away your position. The bigger the lens, the greater the risk of this happening.
Does a longer tube help me?
Not much, though a longer tube has more surface area for the rings to hold it in position. That helps it stay in place on high recoil weapons. On the other hand, a longer tube increases the weight and bulk of the gun without increasing overall visibility.
How do I know which rifle scope can give me the best image?
Read the riflescope specifications. The best rifle scopes have a relatively wide lens and provide a high degree of magnification. After all, great light gathering ability is irrelevant if you still can’t see the target clearly.
Being able to magnify the target by a factor of ten or twenty makes it much easier to sight, though that is still hard if the magnified image is blurry. If you hunt in a variety of environmental conditions or a variety of ranges, a variable scope is the best choice regardless of the lens diameter.
How do I read rifle scope specifications?
The rifle scope specifications have two numbers. The first number identifies the magnification. The magnification refers to how much closer you can see the target than you could with the naked eye.
The second number identifies the diameter of the objective lens. For example, a 3-12×50 rifle scope has a 50 mm lens and has variable magnification of 3 to 12 times. A 2-7×32 mm rifle scope has magnification of 2 to 7 times with a lens diameter of 32 mm. The 3-12×50 rifle scope has a magnificent range. This means you can magnify things up to 12 times.
Fixed scopes have a single magnification scope. There is only one number at the start of the scope designation. A good example is a 6×32 rifle scope. It magnifies everything by a factor of 6, and it has a 32 mm lens.
You can’t zoom in or out, so that won’t let you make use of the trick of increasing magnification to increase light collection. On the other hand, fixed power scopes cost less than variable power scopes.
They are faster to aim, too, since you don’t have to mess with the lens. These scopes may have higher quality lenses than variable power scopes, though this depends on the product.
How much magnification do I need?
The ideal level of magnification depends on what you’re shooting. If you’re shooting targets up to one hundred yards away, defending your home or hunting small game that is close by, magnification of 1x to 4x is appropriate.
If you’re shooting targets up to 200 yards, stalking large game or hunting in a closed landscape like a forest, you’ll want a rifle scope with magnification of 5x to 8x. If you’re hunting in an open landscape like deserts and fields or shooting targets more than 200 yards away, you want 9x or better magnification. It can be hard to find rifle scopes with magnification greater than 12x.
How large should the scope diameter be?
In general, firearms with little recoil have a lens diameter of 28 mm or less. This is fine for close range hunting. Firearms with more recoil typically need a rifle scope with 30 to 44 mm diameter lenses. You’ll also want a wider scope if you’re doing low light hunting, such as those who are hunting animals that only come out at twilight.
Larger lenses may be necessary for higher power scopes, such as when you’re shooting long-distance targets. Scopes of 50 mm and up are only practical if you’re shooting extremely long range targets and use higher magnification in low light conditions instead of switching to other methods for sighting targets.
On the flip side, there is no benefit to having a 50 mm sight like a sniper on the gun you use for personal defense or the rifle you use to shoot rabbits in the garden.
Summary
Does scope tube size matter? The short answer is yes, for a variety of reasons. However, bigger isn’t always better, and there are other factors that can affect the quality of the scope than diameter.
