How to Build an Upper Receiver: A Comprehensive Guide
Building an upper receiver is a fundamental skill for anyone interested in the world of firearms and DIY gunsmithing. The upper receiver is the central component of an AR-15 rifle, providing the foundation for the barrel, bolt carrier group, and magazine well. In this comprehensive guide, we will walk you through the steps required to build an upper receiver, ensuring a successful and enjoyable DIY project.
Step 1: Gather the Necessary Tools and Materials
Before diving into the build, it’s essential to gather all the necessary tools and materials. This includes:
– Upper receiver (Mil-Spec or Commercial)
– Barrel
– Bolt carrier group (BCG)
– Magazine well
– Receiver extension and bolt catch
– Safety selector and magazine release
– M4 feed ramp
– Muzzle device
– Bipod, handguard, and other accessories
Step 2: Prepare the Upper Receiver
Begin by thoroughly cleaning and degreasing the upper receiver to ensure a clean and precise build. This will help prevent any issues with fit and function. Once the receiver is clean, apply a light coat of lubricant to prevent corrosion during the build process.
Step 3: Install the Barrel
Align the barrel with the upper receiver and use the barrel nut to secure it in place. Tighten the nut with a torque wrench to the manufacturer’s recommended specifications, typically around 50-55 ft-lbs.
Step 4: Mount the Muzzle Device
Attach the muzzle device to the barrel using the appropriate screws and washers. Ensure the device is securely mounted and that it aligns with the barrel’s rifling.
Step 5: Install the Feed Ramps and Gas Block
Position the feed ramp in the magazine well and secure it with the provided screws. Next, install the gas block above the barrel, aligning it with the gas key. Torque the gas block in place according to the manufacturer’s specifications.
Step 6: Mount the Bolt Carrier Group and Fire Control Group
Attach the BCG to the upper receiver using the proper bolts and torque them to the recommended specifications. Install the bolt and bolt carrier key, and ensure that the charging handle and extractor are in place.
Step 7: Install the Fire Control Group
Insert the fire control group (including the hammer, trigger, and sear) into the upper receiver. Ensure that the safety selector and magazine release are properly installed and functional.
Step 8: Install the Magazine Well and Receiver Extension
Attach the magazine well and receiver extension to the upper receiver using the appropriate screws and torque them to the recommended specifications.
Step 9: Assemble and Test the Upper Receiver
Finally, assemble the upper receiver with the lower receiver and test the firearm to ensure it functions correctly. Check for any issues with the ejection pattern, feeding, and safety features.
Conclusion
Building an upper receiver can be a challenging but rewarding project. By following this comprehensive guide, you’ll be well on your way to creating a custom firearm that suits your needs and preferences. Remember to always prioritize safety and consult with experts if you encounter any difficulties during the build process. Happy building!
