How to Assemble AR 15 Upper Step by Step: Top 6 2024 Guide

Mastering the DIY AR-15 Upper Assembly: Key Steps and Safety Tips

If you’re looking for how to assemble AR-15 upper step by step, you’ve come to the right place. Let’s dive into the essentials right away:

Key Steps for AR-15 Upper Assembly:
1. Prime the Upper: Clean the upper receiver.
2. Install Dust Cover: Secure the dust cover and ejection port cover spring.
3. Install Forward Assist: Mount the forward assist button and spring.
4. Barrel Installation: Position the barrel and secure it with the barrel nut.
5. Gas System Setup: Install the gas block and gas tube.
6. Handguard Installation: Bolt the handguard onto the upper.
7. Attach Muzzle Device: Screw on the muzzle device securely.

Building your AR-15 upper receiver is rewarding and empowering, giving you a customizable gun to meet your needs. Why build it yourself? You get to choose the components, achieve precise performance, and gain hands-on experience.

Safety First: Always follow manufacturer guidelines, wear safety glasses, and keep your work area clean. Missteps can lead to malfunctions or safety hazards. Take your time, and don’t rush any step.

Ready to get started? Let’s make this build a satisfying project from start to finish.

Essential Tools and Parts for Assembling an AR-15 Upper

Before diving into the step-by-step guide on how to assemble an AR-15 upper, let’s make sure you have all the necessary tools and parts. Having the right tools is crucial for a smooth and efficient build.

Tools You Need

1. Armorer’s Wrench
   The armorer’s wrench is a multi-purpose tool essential for tightening and loosening various parts of the AR-15 upper. It ensures you can properly secure the barrel nut, which is critical for the stability of your build.

2. Allen Keys
   Allen keys, or hex keys, are necessary for tightening screws and bolts on your AR-15. These are commonly used for securing the gas block and other small parts.

3. Anti-Seize Lubricant
   Anti-seize lubricant is crucial for preventing galling and corrosion between metal parts. Use a lubricant that contains either aluminum or copper, but make sure it is graphite-free to avoid galvanic corrosion. Apply it to the threads and contact surfaces to ensure smooth assembly and future disassembly.

4. Vise
   A vise is an optional but highly recommended tool. It holds your upper receiver securely in place, making it easier to work on. This is especially useful when tightening the barrel nut or installing the gas system.

5. AR-15 Barrel Vise Block
   The AR-15 barrel vise block is another optional yet useful tool. It holds the barrel securely in place while you work on attaching it to the upper receiver. This helps prevent any damage to the barrel or upper receiver during assembly.

Parts You Need

• Upper Receiver: The main component where all other parts attach.
• Dust Cover: Protects the upper receiver from debris.
• Forward Assist Button: Helps in manually closing the bolt.
• Charging Handle: Used to charge the weapon.
• Bolt Carrier Group: Contains the bolt and firing pin.
• Locking Barrel Nut: Secures the barrel to the upper receiver.
• Handguard/Rail: Provides a place to grip and mount accessories.
• Gas Block: Directs gas from the barrel to cycle the action.
• Gas Tube: Channels gas from the gas block to the bolt carrier group.
• Muzzle Device: Reduces recoil and muzzle rise.

Having all these tools and parts ready will make your assembly process much smoother. In the next section, we will start with Step 1: Installing the Barrel.

How to Assemble AR 15 Upper Step by Step

Step 1: Install the Barrel

First, secure your upper receiver in a vise using an AR15 barrel vise block. Apply anti-seize lubricant to the barrel extension and the threads on the upper receiver. Insert the barrel into the receiver, aligning the positioning pin with the notch in the receiver.

Next, thread the locking barrel nut onto the receiver by hand. Tighten it using an armorer’s wrench. Ensure it’s torqued to the manufacturer’s specifications, usually between 30-80 ft-lbs. This secures the barrel firmly in place.

Step 2: Install the Gas System

With the barrel installed, it’s time to set up the gas system. Slide the gas block over the barrel, aligning it with the gas port hole. Insert the gas tube into the gas block, ensuring the larger hole faces downward.

Use a roll pin to secure the gas tube in place. Carefully hammer the roll pin into the gas block, using a roll pin punch for best results. Then, slide the gas block assembly over the gas port on the barrel, aligning it perfectly. Tighten the set screws on the gas block to secure it.

Step 3: Install the Handguard

Next, slide the handguard/rail over the barrel and gas system. Align the top rail of the handguard with the rail on the upper receiver. Handguards often have proprietary installation steps, so refer to the manufacturer’s instructions.

Typically, secure the handguard using set screws or a clamping mechanism. For M-LOK systems, ensure the slots are aligned properly for mounting accessories. Tighten all screws according to the handguard‘s instructions to prevent any movement.

Step 4: Install the Muzzle Device

Thread the muzzle brake or other muzzle device onto the barrel. Use a crush washer between the muzzle device and the barrel to ensure proper alignment. Hand-tighten the device first, then use the armorer’s wrench to torque it down.

Ensure the ports on the muzzle brake are correctly oriented, usually with the largest port facing upwards to minimize muzzle rise. This may take a few attempts to get perfect alignment.

Step 5: Install Dust Cover and Charging Handle

If your upper receiver doesn’t have a pre-installed dust cover, start by inserting the rod through the dust cover and the receiver. Secure it with the retaining spring and C-clamp.

Next, flip the upper receiver upside down. Insert the charging handle into its designated slot, followed by the bolt carrier group (BCG). Slide both components into the receiver simultaneously until they lock in place.

Step 6: Install the Butt Stock

Finally, attach the butt stock to the buffer tube. For a Magpul CTR carbine stock, squeeze the locking lever and pull the metal pins down to clear the longest length setting on the buffer tube. Slide the stock onto the tube and adjust it to your preferred position.

With these steps complete, you’ve successfully assembled your AR-15 upper receiver. Next, we will cover adjustments and troubleshooting to ensure your build functions smoothly.

Adjustments and Troubleshooting

Even after assembling your AR-15 upper receiver, you might need to make a few adjustments to ensure everything works perfectly. Let’s focus on gas system tuning and handguard alignment.

Gas System Tuning

Proper gas system tuning is crucial for your AR-15’s reliability and smooth operation. The gas system controls the amount of gas that cycles the bolt carrier group, and improper tuning can lead to malfunctions.

1. Adjustable Gas Block: If you have an adjustable gas block, you can fine-tune the gas flow. Start by fully opening the gas block. Test-fire the rifle and gradually close the gas block until the rifle cycles reliably without excessive recoil.

2. Fixed Gas Block: For a fixed gas block, adjustments are limited. You may need to change the buffer spring or buffer weight to achieve optimal performance. A heavier buffer can help reduce recoil, while a lighter one can improve cycling.

3. Check Alignment: Ensure the gas block is perfectly aligned with the gas port on the barrel. Misalignment can cause gas leaks and cycling issues. Use a pencil and a credit card to draw alignment lines on the barrel and gas block for precision.

Pro Tip: Use a .025-inch spacer to create a small gap between the gas block and the shoulder on the barrel. This ensures proper gas flow and alignment.

Handguard Alignment

A misaligned handguard can affect accuracy and aesthetics. Here’s how to ensure your handguard is perfectly aligned:

1. Install the Barrel Nut: Tighten the barrel nut to the manufacturer’s specifications using an armorer’s wrench. This is crucial for the handguard to fit correctly.

2. Align the Handguard: Slide the handguard over the barrel and align it with the upper receiver. Make sure the top rail of the handguard is flush with the upper receiver’s rail.

3. Tighten Set Screws: Most handguards use set screws or clamps to secure them in place. Tighten these screws evenly to avoid tilting the handguard. Use a mini torque wrench if available to ensure even pressure.

4. Anti-Rotation Devices: Some handguards come with anti-rotation tabs or devices. Install these as per the manufacturer’s instructions to prevent the handguard from rotating during use.

Quick Tip: Follow the specific instructions provided with your handguard. Different brands have slight variations in installation procedures.

By carefully tuning the gas system and aligning the handguard, you can ensure your AR-15 upper receiver functions reliably and looks great. If you encounter any issues, revisit these steps and make necessary adjustments.

Next, we’ll answer some common questions about AR-15 upper assembly to help you further refine your build.

Frequently Asked Questions about AR-15 Upper Assembly

What parts do I need for a complete AR-15 Upper?

To build a complete AR-15 upper, you’ll need the following parts:

• Upper Receiver: This is the core component that houses the bolt carrier group and connects to the lower receiver.
• Barrel: Determines the caliber and accuracy of the rifle.
• Bolt Carrier Group (BCG): Essential for the firing process, including the bolt, carrier, and firing pin.
• Gas Block and Gas Tube: These direct gas from the barrel back to cycle the action.
• Handguard: Provides a grip surface and mounts for accessories.
• Muzzle Device: Such as a flash suppressor or muzzle brake, attached to the end of the barrel.
• Charging Handle: Used to manually cycle the action.
• Forward Assist and Dust Cover: Help ensure reliability and keep debris out of the action.

How much does it cost to build an AR Upper?

The cost to build an AR upper can vary widely depending on the quality and brand of parts you choose.

• Budget Build: $300 – $500. Using basic, no-frills components.
• Mid-Range Build: $500 – $1,000. Incorporates better materials and features.
• High-End Build: $1,000+. Premium parts for superior performance and aesthetics.

Budgeting Tips:
– Plan Ahead: List all parts and tools needed before starting.
– Shop Sales: Look for discounts, especially around holidays.
– Buy Used: Consider reputable second-hand parts to save money.
– Prioritize: Spend more on critical components like the barrel and BCG.

What is needed to complete a stripped upper?

If you start with a stripped upper receiver, you’ll need an upper parts kit to complete it. Here’s what you’ll need:

• Stripped Upper Receiver: The bare upper without any components installed.
• Upper Parts Kit: This typically includes the forward assist, ejection port cover, and related springs and pins.
• Barrel Assembly: Barrel, barrel nut, and any necessary shims or washers.
• Gas System: Gas block and gas tube.
• Handguard: Along with any required mounting hardware.
• Muzzle Device: And appropriate crush washer.
• Charging Handle: To cycle the action.
• Bolt Carrier Group (BCG): To complete the firing mechanism.

By gathering these parts and following a detailed assembly guide, you can successfully build a functional and reliable AR-15 upper receiver.

Next, we’ll dive into the essential tools and parts needed for assembling an AR-15 Upper.

Conclusion

Building your own AR-15 upper assembly can be a rewarding experience. It allows you to customize your firearm to your exact preferences and needs. Let’s review the key points and some maintenance tips to ensure your build remains in top condition.

Review

We’ve covered how to assemble an AR-15 upper step by step, starting from installing the barrel to adding the dust cover and charging handle. Here’s a quick recap:

1. Install the Barrel: Secure the barrel to the upper receiver using a barrel nut.
2. Install the Gas System: Attach the gas block and gas tube.
3. Install the Handguard: Secure the handguard to the barrel nut.
4. Install the Muzzle Device: Attach the muzzle brake or flash suppressor.
5. Install Dust Cover and Charging Handle: Complete the upper with the dust cover, charging handle, and bolt carrier group.
6. Install the Butt Stock: Attach the butt stock and buffer tube (if not already part of the lower assembly).

Maintenance Tips

To keep your AR-15 in peak performance, regular maintenance is crucial:

• Clean Regularly: Clean the barrel, gas system, and bolt carrier group after each use. This prevents buildup and ensures reliable operation.
• Lubricate: Use appropriate gun oil on moving parts like the bolt carrier group and charging handle. This reduces wear and tear.
• Check for Wear: Regularly inspect parts for signs of wear or damage. Replace any components that show excessive wear.
• Torque Settings: Ensure all screws and bolts are torqued to the manufacturer’s specifications. This prevents parts from loosening during use.

Daytona Tactical

If you’re looking for high-quality parts and tools for your build, check out Daytona Tactical. They offer a wide range of AR-15 upper build assemblies and components to suit any build. Whether you’re a novice or an experienced builder, Daytona Tactical has everything you need to complete your project with confidence.

By following these steps and tips, you’ll have a reliable and customized AR-15 upper assembly ready for action. Happy building!

For more detailed instructions, tips, and high-quality parts, visit Daytona Tactical’s AR-15 Upper Build Assemblies.