Mounting a scope on your AR-15 can significantly enhance your shooting accuracy and long-range capabilities. This process, while seemingly straightforward, requires precision and attention to detail to ensure a reliable and accurate zero. This guide will walk you through every step, from selecting the right mount to final adjustments.
Choosing the Right Scope Mount for Your AR-15
The foundation of a successful scope mount is choosing the right type and height. Several factors influence this decision:
Scope Height: Finding the Perfect Eye Relief
The height of your scope mount determines your eye relief—the distance between your eye and the scope's eyepiece. Incorrect eye relief can lead to discomfort, poor sight picture, and even injury. Higher mounts provide more eye relief, which is beneficial for users with longer eye-to-receiver distances. Lower mounts offer a more compact setup but may require a more precise cheek weld.
Consider these factors when determining scope height:
- Your individual physique: Taller shooters may need higher mounts than shorter shooters.
- Your scope's size and magnification: Larger scopes often require higher mounts.
- Your preferred shooting position: A higher mount might be preferable for shooting from prone or sitting positions.
Common AR-15 Scope Mount Heights:
| Height (inches) | Description | Ideal for |
|---|---|---|
| Low (1/3 co-witness) | Allows for co-witnessing of iron sights | Close-range shooting, compact setups |
| Medium (absolute co-witness) | Full co-witnessing of iron sights | Versatile, balance of eye relief and height |
| High (1/2 co-witness) | Minimal co-witnessing or no co-witnessing | Longer-range shooting, increased eye relief |
Scope Mount Types: Understanding the Options
Several types of scope mounts cater to different needs and preferences:
- Picatinny Rails: The most common mounting system for AR-15s. These rails provide a standardized interface for attaching scopes and other accessories.
- Weaver Rails: Similar to Picatinny rails, but with slightly different spacing. While less common, many mounts are compatible with both systems.
- One-Piece Mounts: Offer a rigid, lightweight solution that directly attaches to the upper receiver. These are often the most robust option.
- Two-Piece Mounts: Provide more adjustability and potentially better recoil absorption, but can sometimes be less rigid than one-piece mounts.
- Offset Mounts: These mounts position the scope at an angle, typically used for red dots or close-range optics.
Choosing the right mount type depends on factors such as:
- Budget: One-piece mounts are generally more expensive, but often offer superior rigidity.
- Intended use: Two-piece mounts are more versatile for specific requirements.
- Weight considerations: Lightweight mounts are better for reducing overall rifle weight and improving handling.
Tools and Materials You'll Need
Before you begin, gather the necessary tools and materials:
- AR-15 Rifle: Clean and clear of obstructions.
- Scope: Ensure it's compatible with your chosen mount.
- Scope Mount: Selected based on the factors discussed above.
- Torque Wrench: Essential for correctly tightening screws, preventing damage to the mount or rifle.
- Allen Wrenches: Various sizes, depending on your mount and scope.
- Screwdriver (optional): Some mounts may require a screwdriver.
- Gun Oil: For lubricating screws and preventing seizing.
- Cleaning Kit: Remove any debris from the mounting surface.
- Level: Ensure your scope is mounted correctly.
Mounting the Scope: A Step-by-Step Guide
Step 1: Prepare the Upper Receiver:
Carefully clean the upper receiver's Picatinny rail to remove any dirt or debris. This ensures a secure and proper mount fit.
Step 2: Attach the Scope Mount:
Align the scope mount with the Picatinny rail. Securely attach the mount using the appropriate Allen wrenches. Use a torque wrench to tighten screws to the manufacturer's specified torque. Over-tightening can damage the mount or receiver.
Step 3: Mount the Scope:
Carefully place the scope into the scope mount. Ensure it's properly seated and aligned. Tighten the scope rings with the correct torque specified by the mount and scope manufacturers.
Step 4: Verify Alignment:
Use a level to ensure the scope is perfectly level, both horizontally and vertically. This is crucial for accuracy. Minor adjustments can be made using the elevation and windage adjustments on the scope.
Step 5: Test and Zero:
Take your rifle to the range and proceed with zeroing your scope. Zeroing is a process of adjusting the scope's elevation and windage to ensure your shots hit your target at various distances. Consult your scope's manual for guidance on the specific zeroing procedure.
Maintaining Your Scope Mount
Regular maintenance is key to ensuring your scope remains securely mounted and performs at its peak:
- Periodically check the tightness of all screws: Ensure they remain securely fastened.
- Clean and lubricate the mount: This will help prevent seizing and maintain proper function.
- Inspect the mount for any signs of damage: Replace the mount if you notice any cracks, bending, or other signs of wear.
Proper scope mounting is critical for accuracy and reliability. By following these steps, you can confidently mount your scope and prepare for your next shooting session. Remember, safety is paramount. Always handle firearms responsibly and follow all applicable safety regulations.