Read This Before Buying a Rifle Scope

There is almost no task in which you might use a rifle that cannot be made easier by the addition of an appropriate optical sight. From the earliest primitive telescopes to today’s bulletproof, technology-packed red-dot sights, the right optic is a huge advantage for any shooter. But just like the rifles themselves, not all optics are created equal, and none are suited to every single role, though some come close.

The optics market is easily as crowded as the gun market, with dozens of manufacturers offering a wide array of models, variants and options for every mission, preference and budget. Knowing what you need or want on your rifle is only one half of the task, the other will be choosing a scope or sight from among a half-dozen contenders.

This article will offer advice, theory and considerations for choosing the right sighting solution based on your requirements or anticipated conditions, as well as tips and more nuanced insights to ensure your chosen optic will help you put lead on target.

Beyond Iron Sights – Optic Theory

As I mentioned above, optics are an enormous advantage in nearly any situation, whether they are magnified or not. Broadly speaking, a red-dot or telescopic sight help the shooter aim better. A red-dot, holographic or similar 1x magnification sight accomplishes this by removing completely the requirement to align two separate sighting components (the front and rear sight) as well as the need to focus on the front sight to achieve high accuracy.

By using a single aiming point, or reticle, and superimposing it on the target, errors in alignment are reduced or eliminated. A target-focus versus front sight focus allows better situational awareness and perception of what the target is doing as the shot is being prepped, affording more opportunity for correction. Since the number of elements in the sight picture is now two (reticle and target) instead of three (rear sight, front sight, target) complexity is reduced and this reduction yields greater speed due to less demand on the shooter’s brain.

Magnified optics, whatever reticle they utilize, overcome one of the principal shortcomings of any rifle: the limitations of the shooter’s eye when resolving a distant target. A rifle scope, magnifier, or similar sight makes a distant target appear larger when viewed though the optic, and in conjunction with the reticle allows far finer aiming, making precision shot placement much easier to achieve.

man with a rifle and rds

Telescopes require more skill from the shooter to maximize, as nearly any rifle cartridge is effective and accurate far beyond the limitations imposed on it by the shooter’s vision. Consistency and practice are key to good results with a magnified optic; you’ll need to learn how to eliminate detrimental optical phenomena as well as adjust the scopes settings and learn the reticle’s capabilities, if applicable. They are also, as a rule, more expensive and complex to set up than red dot or similar sights, requiring separate rings or bases, precise zeroing procedures and more care in general, being in all essential features precision-manufactured tiny telescopes.

Either one is a massive leap in capability and efficiency over iron sights, and well worth your dollars and training time to implement. Below we will discuss the best applications for each type of optic.

The Rule of the Red Dot Sight

Red dot sights, or RDSs are nearly ubiquitous today on rifles and carbines, and heading that way pretty soon for handguns. Any close-range shooting situation that requires speed and precision will be made far easier by adding a red dot to your rifle. What is close range in this case? Depends on who you ask: the accepted “maximum” range that an average shooter will tell you a red dot is good to is around a hundred yards.

That assertion is not 100% true essentially, but practically it is decent advice: red dots work well as far away as you can shoot well. Since they do not have magnification, for an average rifle shooter this will actually be around 100 yards or so depending on various factors. A skilled shooter with good eyes can take a red dot sighted rifle out to 200 yards and beyond, but accuracy will be limited by how well you can see the target and the reticle’s relationship to it. The size of the reticle too plays a big part, as a larger reticle, while great for close, fast work, will cover more and more of the target the farther away it is.


For a general purpose defensive or duty rifle, you can hardly go wrong with an RDS, as the vast majority of shootings in any scenario save battlefield combat occur well within 100 yards. RDSs are also entirely appropriate for hunting in more built-up or dense terrain where long shots are unlikely to present themselves. Also RDSs, unlike iron sights and magnified optics, do not require that the shooter’s eye is precisely in line with the lens, and wherever the reticle is perceived is where the round will strike.

Modern RDSs are extremely tough, compact, light, and some have nothing short of ludicrous battery life. These wondrous devices are in fact so reliable and effective we are seeing them installed on more than few rifles with no accompanying backup iron sights! That is hard for some people to swallow, but it is true; even a decade ago there would be very few who would have enough trust in an electronic sight to omit their irons.

Often times you’ll hear some of these electronic, non-magnified sights described as holographic or reflex sights. Is there a difference? Does it matter? Yes and no; the difference between a holographic sight, like the common EOTech HWS series and a reflex sight, like an Aimpoint Comp series sight, is simply one of how the reticle is created on the lens.

Very basically, a holographic sight uses a laser and an etched plate to project a reticle sandwiched between two plates forming the lens. A reflex sight uses an LED to project a dot of light on a lens which is essentially a one-way mirror designed to reflect it. For all practical purpose, there is little difference between the two systems, you simply look through the optic, see a reticle floating out in space, place it on the target, and break the shot. Both are lumped into the broad category of “Red Dot Sight,” and you’ll hear them referred to as such often.

There are some important differences though. Holographic sights are more complex and use a laser, this means they are significantly more power hungry than reflex sights, and not as rugged, all things being equal. Reflex sights’ battery lives are usually measured in 10’s of thousands of hours, even on a bright setting. A holographic sight will do well to even hit several hundred hours when on a modest setting.

A significant perk of holographic sights, though, is the fact that when adding a magnifier to your sight their reticle will stay the same size to the shooter’s eye, affording more precision at longer ranges. A magnifier used with a  reflex sight will see the size of the reticle grow proportionally to the magnification, and so while it will allow you to see the target better the reticle will still be very large in comparison and make precision shooting more challenging.

When selecting an RDS, bear in mind you largely get what you pay for, with more expensive sights having far greater durability, battery life and optical clarity than cheaper models. Sturdy, basic red dot sights can be had starting around $200. Anything cheaper than that should likely be reserved strictly for a fun gun. Anything under $100 is likely not worth your money or trouble. Pay attention to the type of batteries used, as ones that require expensive or hard to locate varieties will be an added cost and logistical strain.

A great many of these sights do include a mount, or have their mount integrated into their design, saving you a little cash, and they are usually of adequate quality to ensure your optic can hold its zero through some bumps and rough handling. Better optics, or aftermarket mounts may include quick-detach functionality and often rugged enough to withstand utterly abusive treatment with no loss of zero.

Vortex StrikeFire Scope for AR 15

Popular options in the RDS market include:

  • Vortex StrikeFire II and Sparc II – Solid, affordable sights from a manufacturer that prides itself on good magnified optics and peerless customer service.
  • Trijicon MRO – A high-quality, compact offering from one of America’s premier provider’s of combat optics. Modestly priced, and very rugged.
  • EO Tech HWS variants – EOTech sights are holographic, with generous field of view and an excellent reticle that combines a fine dot with a large circle for speed and precision. Caution: known battery hogs and have suffered from iffy reliability and a major lawsuit recently. Nevertheless they have staunch advocates.
  • Aimpoint PRO, Comp and Micro series –The Cadillac of RDSs. Ultra-reliable, ultra-long battery life and just short of invincible. Expensive as a rule, but they have a few cheaper models that are still worthy of the name.

Before you purchase, any reputable dealer should let you mount a demo model on your rifle to see how you like it.

Eagle Vision: Magnified Optics

Telescopic sights have been around for ages, and excepting huge strides in technology and refinement, their function has remained unchanged: help the shooter see farther and aim with better precision. Compare to RDSs, you’ll see dramatically more variation in the capabilities, features and sizes of scopes. Scopes are described by a few essential characteristics, usually by their magnification range, expressed as “power,” and the diameter (in millimeters) of the objective lens, which is the front of the scope that transmits light, and ergo the image of the target, back to your eye.

Compared to an RDS, a scope will require you to position your eye precisely in line with the center of the lens to resolve the image correctly. In addition to being centered with the lens closest to your eye, called the eyepiece, your eye must be within a certain distance from it, neither too close or too far, else your view through the scope will shrink, preventing you from aiming properly. This distance is called “eye relief.” Both of these factors are endemic to use of a magnified optic.

The magnification of a scope may be fixed, or variable, meaning adjustable magnification. Examples of few scopes are 4×32, 3-9×40, or 12×50. The first number, or numbers, in our examples expresses the magnification, or “zoom” of the scope. So for our three there they are 4 power, 3 to 9 power, and 12 power. The last number, the diameter of the objective lens tells you how big the scope is generally, and is a basic indicator of how good the field of view and light transmission through the scope will be. Wider objectives let more light in and offer a better field of view as a general rule.

Scopes with very high magnification, 18x plus are mandatory for extreme range shooting, and are usually long and bulky. For rifles that would benefit from magnification but don’t need or cannot achieve that kind of range a scope with less power should be chosen to minimize weight and bulk. A few scopes have comparatively little magnification, like only 2x or 4x and are designed to be compact and offer an edge for the shooter at closer ranges. Variable power scopes can cover most of your bases at the cost of additional weight and expense.

The other most important feature when selecting a scope is the choice of reticle. Reticles come in a variety of basic crosshair configurations all the way through a variety of shapes, drop estimators, and busy, tree-shaped ranging and lead estimating ballistic arrangements. They may be available with battery or ambient-light powered illumination for use in dim conditions or against dark backgrounds, and host of other features.

The choice of reticle is crucial: it is bad to choose something too complicated but worse to choose something too simple. The capabilities of modern ballistic reticles, when given a little practice, allow a shooter to quickly and easily correct a missed shot or apply a hold against a moving target or wind. A simple crosshair may work well enough, but you’ll need a lot more experience, trial and error to get the most from your rifle with one of them.

For a general purpose defensive or duty rifle, the premier magnified optic of our era is called the LPVO: low-power variable optic, a scope that offers magnification up to around 8x, and can usually dial down to 1x, or very near 1x, to allow it to be used with some efficiency at very close range, where scopes have historically been a liability. While costly, and usually heavier than their fixed power relatives, these optics offer excellent versatility and capability in all conditions.

Modern scopes are very rugged and typically hold their zero well when paired with a good mount. Another advantage is the fact you do not have to rely on batteries for basic functionality: if a scope that uses a battery runs out of juice or you simply cannot rustle one up, all you will lose is the ability to illuminate the reticle. Reticles are etched into the lenses themselves and won’t disappear just because you run out of power.

Speaking of mounts, that is a rub when selecting a scope. You’ll need to pick mount or rings to install it on your rifle, as most scopes don’t include them or have an integrated mount. This can introduce a fair bit of complexity and extra cost, as your mount is crucial to ensure accuracy and ruggedness. You’ll need your mount to not only fit the scope tube itself, but also position it at the proper height for you to achieve proper, comfortable eye relief in a variety of positions. This is easier said than done depending on your combination of rifle, scope and mount. Additionally, most mounting solutions for scopes will preclude the use of any iron sights without the removal of the scope or installation of specialty offset backup sights.

another rifle with scope

Like RDSs, you will generally get what you pay for when buying  a scope, and nice ones will often cost significantly more than the rifle you are mounting them on. They are definitely investments! Costs vary dramatically: a solid, dependable, mid-power scope with quality mount may run you anywhere from $500 to over $1000 depending on manufacturer, options, and whether or not it is variable. A long range variable from a world-class manufacturer with a top-tier mount, locking turrets and zero stops will handily cost several thousand dollars. Whatever you are shopping for, you need to be sure you are getting the right tool for the job, as the costs involved with scopes are significant, even for low magnification setups.

There are entirely too many scopes to even begin listing a fraction of them. At any rate, some popular and iconic models are shown below.

  • Vortex Strike Eagle 1-8×24 – A decent offering for those looking to get into the LPVO game on a budget. Feature packed and a good value for a fun gun.
  • Trijicon ACOG series – The legendary ACOG has long been the standard for dead-hard, compact fixed-power combat optics. Costly, and showing their age next to LPVO’s, but still a good choice for a general purpose scope.
  • Bushnell Elite Long Range Hunter 3-12×44 – Bushnell has stepped up their game quite a bit in recent years and is offering quite a few inspired, good quality scopes at competitive prices. For an all-season scope for hunting or other long range work, it is hard to go wrong with this one.
  • Leupold VX-6HD 3-18×44 – Leupold is legendary in optics for their ruggedness, excellent glass and consistency. The VX-6HD is no exception, and a supremely capable scope if you have the coin.

If you don’t know precisely what you are getting into when looking for a scope, head to a dealer. The variables involved with mounting and positioning alone will create headaches if you need to return something or run into an unforeseen problem with installation.

A Word on Optics and Skill

Lots of people will tell you to get an optic because they help you shoot better. In a word, bullcrap!

What?! How can I say that after I spent the past 2,500 words or so telling you how great optics are and what to look for? Hear me out: optics don’t help you shoot better, they help you see better. Now, seeing is a big part of shooting, and seeing better often equates to better shooting, but no optic changes a single thing about the rest of the fundamentals of marksmanship. If you screw those up, a $3,000 optic might as well be a toy telescope.

Indeed, many a new user to scopes report some growing pains thanks to watching that reticle dance all over the target with a mind of its own. Unable to steady it, some shooters get flustered and start shanking shots that they would have nailed with irons. It isn’t the scope making you tremble; it is merely showing you the swaying that was always there. Now all that is left for you to do is try to minimize it and break the shot when it is acceptable.

Similarly an RDS won’t turn Elmer Fudd into John Wick; if your fundamentals are garbage, a red-dot will not shore them up. It will certainly simplify your sighting, but nothing else; not your grip, trigger press or follow-through.

Keep that in mind before you look for a hardware solution to what might be a lack of training or practice.


Chosen judiciously, there is no other accessory that offers the decisive advantages and increase in capability for a rifle shooter that optics do. There is a scope or RDS for every task. By carefully assessing your requirements you can rest assured you’ll install the right sight for your needs.

What’s your favorite optic? Do you run a scope or RDS? Let us know what you think in the comments!

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6 thoughts on “Read This Before Buying a Rifle Scope”

  1. Do you have a preference on first focal plane or second focal plane scopes? I’m a fan of first focal plane scopes for my hunting rifles as I use BDC reticles and thus they stay true on any power I choose. On the other hand my I like to have a second focal plane scope with a simple duplex reticle for my target rifle because as I zoom in on the target the cross hairs stay the same, making it easier to the see.

  2. CY, for long range, I will keep my old Leupold mark 4 LR/Tactical……

    For ARs I like the accushot with a light retical or a Leupold

  3. i am looking for something to drop on my AR with fixed front and rear sighs, something that will cowitness. i still have no idea, what RMR or what RDS. i am looking for.

    general rule on low light choosing of the glass.
    objective glass width/divided by your power. = ?????????
    if your answer is 5 or greater . the better for low light, it works.

    • Black, for general purpose carbine use there is little that will not be served well by an Aimpoint. If cost is no object and you do not mind a little extra weight and bulk, the Comp M4 is an ultra-rugged sight that will be future-proof for some time. If you need to save some coin look into Aimpoint’s Patrol Rifle Optic.

      Mount them up in a lower 1/3rd cowitness mount and you’ll be all set. I’d avoid an absolute cowitness mount with fixed irons as it will clutter up your view through the optic terribly, spoiling one of the biggest perks of an RDS. Hope this helps.


    • I had never used a red dot and was fundamentally opposed to them as all i used, including in the army were iron sights. I recently purchased an aimpoint pro, what i feel to be a good midrange sight and i have to say. I have changed my mind. For anything out to 200 meters it is effective and came with all the hardware to cowitness. Give it a try


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