Understanding Your AR-10 Optic Needs
Caliber Considerations and Ballistics
The .308 Winchester is arguably the most common caliber for AR-10 rifles, but other options exist. Regardless of your chosen round, understanding the ballistic characteristics is vital. A bullet’s trajectory isn’t a straight line; it curves downward due to gravity. The distance the bullet travels, along with the amount of “drop” it experiences over that distance, is essential to know. Wind also significantly affects bullet flight. A crosswind can push a bullet off course, particularly at longer ranges. You must account for both bullet drop and wind drift by adjusting your optic’s elevation and windage settings or using a reticle designed to compensate for these factors.
Determining the Intended Use
What will you primarily use your AR-10 for? This question dictates many aspects of your optic selection.
Hunting: Hunters prioritize optics that are clear and bright, especially in low-light conditions. Magnification ranges typically fall between 2-10x or 3-15x. Features like illuminated reticles can be helpful in the dim light of dawn or dusk. Durability and ruggedness are also important to withstand the rigors of the field.
Target Shooting: Precision and accuracy are paramount for target shooting. High magnification ranges (e.g., 5-25x or even higher) allow for precise shot placement. Adjustable turrets are essential for making fine-tuned adjustments for elevation and windage. Reticles with precise holdover points, such as Mil-Dot or MOA-based reticles, are often preferred.
Competition: Competition shooters often require a combination of speed and accuracy. They might choose scopes with lower magnification ranges (e.g., 1-6x or 1-8x) for faster target acquisition at closer ranges, or mid-range magnification for more distant targets. Illumination, fast adjustments, and robust construction are important.
Home Defense: For home defense, speed and situational awareness are crucial. Optics with lower magnification ranges (e.g., 1-4x or 1-6x) or red dot sights are commonly used. These optics provide a wide field of view for rapid target acquisition at close to intermediate distances. Durability and reliability are of utmost importance.
Understanding Range and Distance
The distances you intend to engage targets at heavily influence your optic choices. Shooting at 100 yards differs significantly from shooting at 1000 yards. For shorter-range shooting, lower magnification might suffice, while longer-range engagements demand higher magnification. Adjustable turrets are essential for making precise adjustments for bullet drop and wind. Parallax adjustment is critical for long-range accuracy; this feature ensures that the reticle remains focused on the target at various distances.
Key Features to Look for in an AR-10 Optic
Magnification Levels and Their Role
Magnification, expressed as a number followed by “x” (e.g., 3-15x), refers to how much closer the target appears.
Low magnification ranges (e.g., 1-4x, 1-6x) are suitable for close- to mid-range engagements, offering a wide field of view for rapid target acquisition.
Mid-range magnification (e.g., 3-15x) is a versatile option, suitable for hunting, target shooting, and general-purpose use.
High magnification (e.g., 5-25x or higher) is ideal for long-range target shooting, enabling you to see and engage distant targets with precision.
Objective Lens Size: Gathering Light
The objective lens is the front lens of the scope, and its size (measured in millimeters) affects how much light the optic gathers. A larger objective lens gathers more light, resulting in a brighter and clearer image, especially in low-light conditions. However, a larger objective lens also increases the overall size and weight of the scope. This is a trade-off between image brightness and the rifle’s overall profile.
Reticle Types: The Viewfinder’s Internal Markings
The reticle is the aiming point within the scope. Various reticle designs are available, each with its strengths.
Duplex/Crosshair Reticles: These are the simplest reticles, featuring a basic crosshair. They are effective for general shooting but lack holdover points for bullet drop or wind.
BDC (Bullet Drop Compensation) Reticles: These reticles feature holdover points specifically calibrated for a particular bullet weight and muzzle velocity.
Mil-Dot Reticles: Mil-Dot reticles use “mils” (milliradians) to measure distance and make adjustments. They are popular in tactical applications, providing a system for estimating range and making windage and elevation adjustments.
MOA-based Reticles: These reticles use MOA (minute of angle) to measure angles. Like Mil-Dot reticles, they offer holdover points and allow for precise adjustments.
Christmas Tree Reticles: These complex reticles, often found in long-range scopes, offer a multitude of holdover points for both bullet drop and windage, allowing for extremely accurate shots.
Turrets and Adjustments: Precision Control
Turrets allow you to adjust the windage (left/right) and elevation (up/down) of the reticle. The adjustments can be based on MOA (minute of angle) or MRAD (milliradians).
Reliable and precise adjustments are crucial for accurate shooting. Look for turrets that offer audible clicks and are easy to operate.
Consider a Zero Stop, a feature that allows you to quickly and easily return to your original zero setting.
Build Quality and Durability: Withstanding the Elements
An AR-10 optic must be built to withstand the stresses of recoil and the elements.
The scope should be constructed from high-quality materials, such as aircraft-grade aluminum.
It should be waterproof, fog-proof, and shockproof to ensure reliable performance in any environment.
Durability is key to maintaining zero and ensuring the scope functions reliably over time.
Eye Relief and Eye Box: Achieving a Clear View
Eye relief is the distance between your eye and the scope’s eyepiece where you can see a full, clear image. The eye box is the area where your eye can move slightly while still maintaining a clear sight picture. A comfortable eye relief and a generous eye box are essential for a positive shooting experience.
Top Optic Recommendations
Optics Best Suited for Hunting
Example: Vortex Viper PST Gen II 2-10×32
Key Features: This scope offers a versatile magnification range, a bright, clear image, and excellent build quality. It typically includes a second focal plane reticle.
Pros: High-quality glass, reliable adjustments, good low-light performance.
Cons: It may be a bit pricier than some options.
Suitability: Excellent for hunting deer, hogs, or other medium-sized game at varying distances.
Example: Leupold VX-Freedom 3-9×40
Key Features: This is a classic hunting scope known for its lightweight design, excellent clarity, and rugged construction.
Pros: Lightweight, reliable, and made in the USA.
Cons: Simpler reticle options, less magnification range.
Suitability: Ideal for hunting in a wide range of conditions, offering simplicity and reliability.
Optics Best Suited for Target Shooting
Example: Nightforce ATACR 5-25×56
Key Features: This scope provides extremely high magnification, superb glass clarity, and precise adjustments for long-range shooting. First focal plane reticles provide consistent holdovers at all magnifications.
Pros: Exceptional image quality, rugged build, precise adjustments.
Cons: Higher price point and heavier.
Suitability: Excellent for dedicated target shooters and those engaging targets at extended ranges.
Example: Bushnell Match Pro ED
Key Features: A purpose-built scope for competition shooting, with high-quality ED glass, a wide magnification range, and a very competitive price point.
Pros: Excellent value for the price, high-performance glass, and easy to use.
Cons: Can be heavy
Suitability: Great for competitions and long-range target practice.
Optics Best Suited for Tactical/Competition Use
Example: Trijicon ACOG
Key Features: Known for its rugged durability, fast target acquisition, and fixed magnification.
Pros: Extremely durable, always-on illumination (uses fiber optics), and quick target acquisition.
Cons: Fixed magnification, less versatility for varying distances.
Suitability: Excellent for tactical applications and fast-paced competition.
Example: Sig Sauer Tango6T 1-6×24
Key Features: This scope provides a low magnification range, a bright illuminated reticle, and excellent build quality.
Pros: Fast target acquisition, durable, and relatively lightweight.
Cons: Lower magnification for extended ranges.
Suitability: Suitable for dynamic shooting, competition, and tactical applications.
Optics Offering Excellent Value for Money
Example: Primary Arms GLx 3-18×44
Key Features: A versatile scope offering a good balance of features, image quality, and price.
Pros: Good glass clarity, accurate adjustments, and a reasonable price.
Cons: Not as durable as some of the more expensive options.
Suitability: A solid choice for general use, target shooting, and hunting on a budget.
Example: Athlon Optics Argos BTR
Key Features: This scope provides a good combination of features, clarity, and value.
Pros: Good glass, durable, and a competitive price.
Cons: May not have the same low-light performance as more expensive optics.
Suitability: A great choice for shooters looking for a budget-friendly optic that delivers solid performance.
Mounting Your AR-10 Optic
Choosing the right scope rings or a one-piece mount is essential.
Quality mounts are made from durable materials and securely hold your optic in place.
One-piece mounts often provide more stability.
Proper installation is critical to ensure the optic is aligned correctly with the barrel.
After mounting, you must bore sight the scope to get you on paper. Then, zero the optic at your desired range.
Maintenance and Care for Your Optic
Proper maintenance ensures your optic functions reliably for years.
Clean the lenses regularly with a soft cloth and lens cleaner.
Store your optic in a cool, dry place.
Protect the optic from impacts and extreme weather conditions.
Conclusion
Choosing the best optic for AR10 is a personal decision. Consider your needs, budget, and the type of shooting you’ll be doing. By understanding the features and capabilities of different optics and following the guidelines outlined in this article, you can select a scope that will enhance your shooting experience and help you get the most out of your AR-10 rifle.
Remember to do your research, compare options, and consider the reputation of the manufacturer. Don’t be afraid to ask for recommendations from experienced shooters. Happy shooting!
