Discover the best AR 10 scope for your needs with our buying guide. Developed in the late 1950s by Eugene Stoner, the AR 10 was one of the first rifles ever marketed by the Fairchild Division of Armalite. It’s also the big brother to the AR 15 rifle and a more powerful battle rifle in its own right.
Although the AR 10 never received much commercial success, many hunters and rifle users have come to love this .308 caliber platform because of its versatility. The AR 10 is ideal for big game hunting, target shooting, home defense, and so much more. It also offers good optics if you want to achieve maximum performance.
What’s The Main Difference Between AR 10 And AR 15 Scopes?
The AR 10 and AR 15 rifles don’t have the same effective firing range. Therefore, what makes scopes for each rifle different is simply the magnification power that’s required to provide optimal telescoping sighting for the supported firing range.
An AR 15’s effective firing range is about 400m to 600m (average 547yards), but it’s possible to take longer shots depending on the ammunition you use and shooting conditions. You can also get 100 to 200 meters more effective firing range with something like .300 blackout ammo. However, even good .223 Remington or 5.56 NATO ammo will start to run out of kinetic energy at 600 to 700 meters when fired from an AR 15. So, there’s really no need to buy a riflescope that can out-range the ammunition you’ll be shooting.
When it comes to the AR 10, effective shooting range for this rifle is usually about 600m to 700m (656 to 765yards), although the .308Win ammo on this rifle can make shots of up to 1000 meters. Remember that a good AR10 scope is also one that provides ample magnification for your desired shooting range.
What to Consider When Shopping For AR 10 Scopes
AR 10 scopes come with a dizzying variety of bells and whistles. It’s therefore easy for first time buyers to get confused over what to buy. The following is a rundown of the most important considerations to make when shopping for AR 10 Scopes.
Magnification
Optimal magnification for any given shooting task is a subjective matter. However, scopes that provide telescopic sighting from 100 to 1000 meters can serve most purposes when using an AR 10 rifle. From a general standpoint, though, the longer the shooting range, the more magnification power you’ll need for your AR 10 riflescope.
In most cases, scopes lower than 10x magnifications are typically better suited for shooting at distances less than 500 meters or for offhand shooting. For long range shooting (up to 1000yards), scopes with 18-25x power would be ideal.
When selecting a scope’s magnification for your AR 10, make sure not to confuse those that have fixed and variable power. Scopes with fixed power usually have a single digit followed an “x”. This figure represents how many times larger an image becomes when viewed through the ocular lens. With variable power scopes, the magnification power is expressed as a range. For example, a 3-9x scope indicates that the level of magnification is adjustable from the lower number to the higher one. Such variable power scopes provide much flexibility since you can use them for both long and short range shooting.
Diameter of the Objective Lens
The objective lens transmits light to the ocular lens in order to focus an image. Usually, the size of objective lenses is expressed in “mm” after the magnification specification. For instance, a scope indicated as 3-9x40mm means that the objective lens has a diameter of 40mm.
A larger objective lens will capture more ambient light than a small one, which means a brighter and clearer image. At higher magnifications (12x upward), the brightness and clarity offered by large objective lenses is quite noticeable.
It’s important to note that a larger objective lens comes with a few drawbacks. For instance, the bulky size of a larger lens adds more weight to your rifle and makes it easier for the scope to accidentally knock into things. Furthermore, a larger objective lens can affect the balance of a rifle since it has to be mounted over the barrel and action. Fortunately, you can compensate for this by buying a cheek riser.
Special Coatings
A good scope will also have quality glass. Special coatings are usually applied on the surface of some riflescope lenses to reduce glare and the amount of light lost during when transmitting the image to your eye. Scopes can have more than one lens coating. Generally, you’ll find special coatings described using the following terms:
- Coated – this means that a single layer has been applied to at least one lens.
- Fully Coated – all air-to-glass surfaces will have one layer of coating.
- Multi-coated – when multiple layers of special coating have been applied to at least one lens.
- Fully multi coated – all air-to-glass surfaces contain more than one layer of special coating.
Keep in mind more special coatings usually translate to a more expensive and high-quality riflescope.
Reticle Type
After determining how much magnification you need, an objective lens size and special coatings, you’ll then have to settle for a reticle pattern. The reticle, also known as crosshair, is a series of lines, dots, or other patterns in the eyepiece that help to locate and aim at targets. There are dozens of reticle patterns designed by different scope manufacturers. These include:
- Duplex: The duplex reticle takes the form of a simple crosshair. However, the crosshair becomes thicker at the outer area of the scope but has finer lines as it converges at the center. This design helps the eye to focus on the center of the scope. Riflescopes with duplex reticles are great choices for target shooting and hunting.
- Mildot: The Mildot reticle is much like the duplex pattern but with a little twist. This reticle has a series of evenly spaced dots that run along the finer lines of the crosshair. The dots can be used for range calculations or as some sort of BDC. Scopes with the mildot reticle are suitable for precision shooting from a range of 300 yards or beyond.
- BDC: BDC is an acronym for “bullet drop compensation”. These types of reticles have markings on the lower crosshair post. The markings represent different target distances. BDC scopes allow you to make accurate shots over different target ranges without adjusting the elevation setting on your scope. However, riflescopes with these types of reticles are only moderately accurate for ranges beyond 500 yards.
When planning to use your AR 10 at dusk or dawn, an illuminated reticle will perform better in low light conditions.
Windage and Elevation Adjustments
Windage and elevation adjustments on most riflescopes are calibrated in MOA (minute of angle) or MRAD (milradian). Both of these measuring units represent a section of an angle that can be converted to linear inches. Once you understand how the MOA or MRAD systems work, you can use these adjustments as a means of measuring an object’s target zone. However, MOA adjustments allow for more accurate zeroing compared to milradian scopes because minute of angle increments are smaller, typically 1/4-inch per click.
Focal Plane
Another important feature to factor in when choosing a scope for your AR 10 is the position of the reticle within the telescopic sight at different magnification settings. This position is usually referred to as the first focal plane (FFP) or second focal plane (SFP).
Scopes equipped with the second focal plane technology allow for a consistent sight picture at all levels of magnification. In other words, the reticle remains the same in size regardless of the magnification level when using an SFP scope. On the other hand, FFP reticles change in size as the magnification changes, and this can make it difficult to see the crosshair at low magnification levels of 3-5x.
Parallax Adjustment
Parallax error can lead to missed shots or bad groupings. It occurs when the scope is not able to focus the reticle and target on the same focal plane. Parallax in riflescopes is detected when the reticle appears to change in position in relation to the target as you move or nod your head. This is usually not a problem with low power scopes, especially those set to be parallax free at a specific distance such as 100 yards. However, parallax can be a problem when using a higher power scope such as those rated at 12x and beyond. It’s therefore important to go for a model that offers a parallax adjustment knob (sometimes called the “side focus”) when shopping for high power scopes.
Eye Relief
Eye relief is simply the maximum distance you can leave between the eye and scope and still obtain the full viewing angle. This distance is usually expressed in inches and it varies depending on the riflescope brand. The AR 10 has greater recoil than the AR 15 since it is a powerful gun and fires larger rounds. As such, the scope that you choose for this rifle should have a decent eye relief range to compensate for the higher recoil rate.
Conclusion
Now that you have a solid idea of what to look for when shopping for an AR 10 scope, the final factor to consider is, of course, your budget. When it comes to riflescopes, you get what you pay for. Most, if not all, high priced rifle scopes will give you increased adjustment precision, better optical clarity, repeatability and overall durability. However, it’s still possible to get budget priced riflescopes that perform well and are of decent quality. The current scope market is flooded with a myriad of brands, which gives buyers on a budget many different price points from which to choose. In order to get the best bang for your buck, make sure to research the brand and model of any low priced scope by reading through what other customers have to say.