Why Choose a Red Dot Sight for Your AR-15?
Rapid Target Acquisition
Perhaps the most significant advantage. Red dot sights allow you to quickly acquire your target because your eye doesn’t need to focus on aligning multiple elements. Simply put the dot on the target and pull the trigger. This speed can be critical in dynamic shooting scenarios.
Enhanced Situational Awareness
Unlike magnified optics, red dot sights provide an unobstructed field of view. You can see your target and everything around it, allowing you to stay aware of your surroundings, something particularly important in tactical or hunting situations.
Ease of Use with Both Eyes Open
Red dot sights are designed to be used with both eyes open. This further improves situational awareness and reduces eye strain compared to traditional iron sights.
Suitable for Various Shooting Distances
Red dot sights are adaptable to various ranges. While they’re excellent for close-quarters combat and rapid engagements, they can also be effectively used for shooting out to several hundred yards, especially with a good quality optic and practiced holdovers.
Reduced Parallax
Parallax is the apparent movement of the reticle when the shooter’s eye position changes. Quality red dot sights minimize parallax, meaning the dot will appear to stay on target even if your eye is slightly off-center behind the optic. This contributes to better accuracy.
Key Features to Consider When Selecting a Red Dot Sight
Reticle
The reticle is the aiming point, the dot you see when you look through the sight. It’s a critical element. Here’s what to consider:
Dot Size
Measured in MOA (Minute of Angle). MOA is a unit of angular measurement; 1 MOA subtends roughly one inch at 100 yards. A smaller dot (e.g., 2 MOA) is better for precision shooting at longer distances because it covers less of the target. A larger dot (e.g., 4 MOA or more) can be faster for close-range shooting, as it’s easier to pick up. The ideal dot size often comes down to personal preference and intended use. Consider what type of shooting you will be doing.
Brightness Settings
A good red dot sight will have adjustable brightness settings. You need to be able to adjust the brightness to match the ambient light conditions. Too dim, and the dot will be hard to see. Too bright, and it can bloom or wash out the target. Look for a sight with multiple brightness settings, including some that are night vision compatible if you plan on using night vision.
Reticle Color
The vast majority of red dot sights use a red dot, which works well in most lighting conditions. Green dots are becoming increasingly popular. Some shooters find green to be more visible, especially in certain environmental conditions like bright sunlight or against green backgrounds. Choosing the right color often boils down to personal preference.
Size and Weight
The size and weight of your red dot sight will affect the balance and handling of your AR-15.
Tube Style vs. Open Reflex
Tube-style red dots are enclosed in a cylindrical housing. They are typically more robust and better protected from the elements. Open reflex sights have a more minimalist design with a small, exposed emitter. They are often lighter and offer a wider field of view, but may be more susceptible to being blocked by debris.
Weight
Consider the weight of the sight and how it affects the overall balance of your rifle. Lighter is generally better for ease of handling, but you don’t want to sacrifice durability. Determine how your sight will affect the weight of your rifle and handle in dynamic situations.
Durability
A red dot sight mounted on an AR-15 needs to withstand the rigors of shooting and the elements. Durability is a vital factor:
Materials
Look for sights made from high-quality materials like aircraft-grade aluminum. This ensures the sight can withstand impacts and maintain its structural integrity.
Water Resistance and Shock Resistance
Your sight should be water-resistant, and ideally, waterproof. Shock resistance is essential to withstand the recoil of the AR-15 and any accidental bumps or drops. Check the specifications for IP (Ingress Protection) ratings to understand the level of water and dust protection.
Recoil Resistance
AR-15s generate significant recoil. Your red dot sight needs to be designed to withstand this constant pounding without losing zero or suffering damage. Ensure the sight is rated for use on rifles and has been tested to handle the recoil forces generated by the AR-15 platform.
Battery Life
Battery life is a crucial consideration, as a dead battery renders your sight useless.
Battery Types
The most common battery types for red dot sights are CR2032 and AAA batteries. Consider battery availability when choosing a sight.
Battery Life Expectancy
Look for sights with extended battery life, measured in hours. Many modern red dot sights boast thousands of hours of runtime, and some even have auto-off features to conserve battery life.
Auto-Off Features
An auto-off feature will automatically turn off the sight after a period of inactivity, prolonging battery life.
Mounting Options
How your red dot sight mounts to your AR-15 is essential for both its secure attachment and compatibility.
Picatinny Rail
The Picatinny rail is the standard mounting platform for AR-15s. Make sure the sight you choose is compatible with the Picatinny rail system.
Mount Height
The height of the mount affects how you align your eye with the sight. This is particularly important if you plan to co-witness with iron sights. Co-witnessing means you can see your iron sights through the red dot. Different mounting heights support different co-witness options (absolute co-witness or lower 1/3 co-witness). Think about your preferred shooting style and your other accessories when deciding.
Adjustments
The ease and precision of adjustments are important for zeroing and making corrections.
Windage and Elevation
All red dot sights have windage and elevation adjustments to zero the sight.
Adjustment Increments
The adjustment increments (e.g., 1/2 MOA, 1 MOA) determine how much the point of impact shifts with each click of the adjustment dials. Smaller increments allow for more precise adjustments.
Budget
Red dot sights range widely in price, and it’s important to balance features with your budget.
Price Range
Red dot sights can range from under a hundred dollars to several hundred dollars or more.
Balancing Features with Cost
Determine your needs and prioritize the features that are most important to you. Focus on what you will be using the sight for and determine which is the best choice given your budget.
Top Red Dot Sight Recommendations
Entry-Level/Budget Options
These sights provide excellent value for the price, making them ideal for those new to red dot optics or for budget-conscious shooters.
Vortex Crossfire
The Vortex Crossfire is a popular choice for its affordability and reliable performance. It offers a clear, bright red dot, multiple brightness settings, and robust construction. It offers a great option to those looking to get their first red dot.
Sig Sauer Romeo Series
The Sig Sauer Romeo series offers a range of red dot sights at different price points, all known for their quality and features. The Romeo5 is especially popular for its value.
Mid-Range Options
These red dot sights offer a step up in features, durability, and performance.
Holosun HS510C
The Holosun HS510C is a favorite among many shooters. It features a solar failsafe, which extends battery life. Also, it offers a circle-dot reticle that allows for quick target acquisition.
Aimpoint PRO (Patrol Rifle Optic)
The Aimpoint PRO is a rugged and reliable red dot sight designed for law enforcement and military use. It offers exceptional battery life and a crisp, clear dot.
High-End/Premium Options
These sights represent the best in red dot technology, offering superior features, durability, and performance.
Aimpoint CompM5
Aimpoint is a leader in red dot technology, and the CompM5 lives up to the name. It offers incredible durability, long battery life, and a clear, crisp dot.
Trijicon MRO
The Trijicon MRO (Miniature Rifle Optic) is known for its clear glass and compact size. It’s a great choice for shooters who want a high-quality sight in a smaller package.
Mounting and Zeroing Your Red Dot Sight
Mounting
1. Ensure your AR-15 is unloaded and the magazine is removed. Confirm your rifle is safe to handle.
2. Attach the mount to the Picatinny rail on your AR-15, ensuring it’s securely fastened. Follow the manufacturer’s instructions.
3. Attach the red dot sight to the mount. Secure the sight with the appropriate screws or locking mechanisms.
Zeroing
1. If possible, use a bore sighter to get your red dot roughly aligned with the bore. This will save you time and ammunition at the range.
2. Set up a target at a known distance (e.g., 25 yards).
3. Take a few shots, aiming at the center of the target.
4. Observe where your shots impact.
5. Adjust the windage and elevation turrets on your red dot sight to move the dot to the point of impact. Each click will move the dot a certain amount, based on your sight’s adjustment increments. Adjust the turrets based on where your shots landed.
6. Repeat the process, firing groups of shots and adjusting the sight until your point of impact matches your point of aim.
Zeroing at Different Distances
You might zero your sight for a specific distance (e.g., 50 yards). If you intend to shoot at longer distances, you will need to account for bullet drop. Some shooters prefer to zero at 50 yards, while others zero at 100 yards. Consider your typical shooting distances when deciding.
Care and Maintenance
Cleaning
Clean the lens regularly with a soft cloth or lens cleaning solution. Avoid harsh chemicals.
Battery Replacement
Replace the battery when the dot appears dim or stops illuminating. Keep spare batteries readily available.
Storage
Store your red dot sight in a dry, protected environment when not in use.
Checking the Sight
Periodically check the sight for any loose screws or damage.
