Choosing the Correct Rifle Scope

With the thousands of different options for rifle scopes out there, picking one out can be very difficult task. The biggest question most people ask is what is the best scope for the money? Well, this is a difficult question to answer. There are several factors that must be considered before that question can be answered. First, what am I going to use the scope for and second, what is the budget? Most shooters just buy a scope based on past experience and from what other shooters tell them what has worked for them. However, all shooters are not the same. One person’s eyesight can be totally different that another person. Also one person may have a different cheek positioning on the rifle stock compared to another person which will change the head positioning behind the scope causing one scope to work great while another scope will black out on the edges. Below are several factors that you should consider when purchasing a rifle scope:

  1. Magnification
  2. Objective diameter
  3. Reticle
  4. Eye relief
  5. Field of View
  6. Parallax Adjustable/ Adjustable Objective
  7. Turrets
  8. Tube Diameter
  9. Light Transmission
  10. Exit Pupil
  11. Brand


There are two types of magnification that scopes come in, a fixed and a variable.

Fixed Power – A fixed power scope is manufactured to be at one specific power and cannot be changed, for example a 6×42. Typically a fixed power scope is more reliable than a variable, but gives you the disadvantage of not being able to change the power if needed. Another advantage is typically a fixed power scope will be a little brighter and clearer due to have one less lens for the light to travel through the scope.

Variable Power – One big advantage for the variable power scope is that it is more versatile in various shooting situations. The majority of scopes designed today are variable power for this reason. Having the ability to change powers gives the shooter more options when hunting under different situations.

Objective Diameter

Objective diameter is the measurement of the objective lens on the end of the scope. The most popular sizes are the 32 mm, 40mm, and 50mm, but are available in other sizes as well. The objective lens is one of the determining factors in how much light can be passed through the scope. One similar power’s, a 50mm objective will allow more light to your eye compared to a 40mm scope. However, when moving up in objective size, the heavier the scope will be and must be mounted higher on the guns receiver. Sometimes this can cause a problem, not allowing the shooter to position there head on the stock in a consistent manor every time. When choosing an objective size, consider what power the scope will be used at mostly, the higher the power, the bigger the objective lens. This will allow the maximum light to transfer through the scope during low light hunting situations.


When it comes to reticles, every shooter/ hunter has their preference. Manufacturers are developing reticles for every shooter out there, from the mil dot, a standard duplex to the advanced reticles like the MOA and BDC (Bullet Drop Compensate) for long range shooting. Leupold offers reticles like the Boone & Crockett, Varmint Hunter and TMOA reticles, where Vortex manufacturer’s reticles like the VMR-1 and EBR-1. Another popular reticle is the Mil-dot which offers a ranging estimating capability that was developed for military applications. This reticle is now becoming a popular reticle for long range shooting and even hunting situation.

Eye Relief

Eye relief is one of the most critical measurements when deciding on a scope. For example, a handgun scope with eye relief of 20 inches will not be suitable for a rifle and a scope with a short eye relief (3 inches or less) will not be a good idea for someone shooting a high caliber like a magnum rifle. Heavy recoil firearms like shotguns and high-caliber rifles should be coupled with optics that has longer eye-relief ranges for the safety of the shooter.

Field of View

When looking at a scope, each one is manufactured slightly different which will cause the field of view to vary from one scope to another. When hunting in thick cover with close shots, a wide field of view will be very beneficial. This will allow you to pick up the target quickly. The more you can see the faster you can pick up the target. When shooting longer distances, the field of view is not as critical.

Parallax Adjustable

Parallax adjustment is another important factor especially if you are shooting at distances greater than 100 yards. Parallax occurs when the primary image of the object is formed either in front of, or behind the reticle. If the eye is moved from the optical axis of the scope, then parallax is created. High magnification scopes or scopes for long range shooting, where even slight sighting errors would be magnified, should be equipped with a parallax adjustment such as an adjustable objective or a side focus parallax. Deciding whether to get a scope with an adjustable objective or side focus is up to you, but there are advantages to each. An adjustable objective typically has the capability of focusing down closer for short distance shooting like with a rimfire or air rifle, where a side focus is each to adjust without having to move your rifle or head too much.


Turret adjustment and turret style are also important depending on your type of shooting. Turrets are offered exposed or covered, 1/2 MOA adjustment to 1/8 MOA. Each one is suitable for specific needs such as hunting to precise target shooting. As for turret style, exposed turrets are typically used for target shooting where it makes for easier adjustment when changing distances to the target. Covered turrets are typically used on hunting rifles because the scope is sighted in once and is not changed after that.

Tube Diameter

Scopes are made in several different tube sizes, with most scopes being manufactured with a 1 inch or 30mm but now are being made in a 34mm or 35mm main tube. Tube diameter is often misunderstood being able to allow more light through the scope to the eye. This is false. The main factors for the amount of light through the scope are lens coatings, objective size and magnification. Most come hunting scopes are manufactured with a 1 inch tube and a 30mm in tactical and long range style scopes Scopes made with a 30mm tube diameter and larger are bigger in size, strong and typically have the advantage of offering more adjustment with the turrets. This is very important when using high magnification scopes and adjusting them to shoot long ranges.

Light Transmission

Light transmission is the measurement of the amount of light that can be transmitted through the lens of the scope. When comparing scopes, a high quality scope typically offers light transmission of 95% or higher. This means that 95% of the light can be transmitted through the lens without being reflected away from the lens. Other factors are involved as well. Magnification actually makes a difference in how much light is passed through the scope as well. Poorly made scopes with high magnification scopes will look foggy as light begins failing at dusk. If you have the shooting opportunity of a lifetime, you do not want to miss out because you bought a junk scope. This clarity is also seen during the day. A scope with good light transmission will be easier on your eyes to focus on even.

Exit Pupil

Exit pupil is a measurement of light that is transmitted through the scope to your eye. This calculation is done by taking the objective lens and dividing it by the power or magnification. For example, you have a rifle scope that is a 3-9×40; you take 40 divided by say a power of 4 this gives you an exit pupil of 10mm of light. Now let’s take into consideration the same scope at 9 power. If you use the same calculations at the above example, you will see the exit pupil is 4.4mm, substantially less than at 3 power.

Why is this number important? When the light begins to fade at the end of the day, the higher the exit pupil the longer you can see through the scope. Now a healthy human eye pupil can only dilate to about 7mm’s, so any measurement above 7mm’s is actually not accepted by the eye and is just wasted. As a person gets older, the eye’s ability to adapt to low light situations decrease, effecting the amount of exit pupil light that it can accept.


Brand is probably the most argued topic in the optics world. Most brands make good scopes, but there are brands out there that make junk and I personally would stay away from. The most popular saying the optics world is, “you get what you pay for”. Within brands you will see be a substantial different between models, for example a Leupold VX-6 and a Leupold VX-1 rifle scope. But between manufactures you can find some quality optics for a reasonable price, such as the Clearidge, Nikon, Vortex and Burris lines. If Leupold, Zeiss, and the other top brands are out of your price range than take a look at the other brands mentioned previous to save some money without losing quality.

Purchasing a scope for that favorite rifle can be made simpler by just knowing the basic terminology of the rifle scope. This will give you the confidence that you purchased a quality scope in your price range that can last you a life time.

If you have any other questions or need help with anything else, don’t hesitate to call us our send us an email at

You can also read about choosing the correct binoculars!

One Response to “Choosing the Correct Rifle Scope”

  1. Tommy simpson

    I’ve shot Simmons rifle scopes for deer hunting without a real issue that I can say is the scopes issue from deer to squirrels Simmons gets it done


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