The AR-10 was developed in the late 1950s by Eugene Stoner. It was initially chambered for the 7.62×51 mm NATO with an aluminum alloy receiver and fiberglass material on the stock, handguards, and pistol grips. It was designed as a combat rifle but was never adopted by the U.S military. There was a demand for a lighter rifle whereby the AR-10 gave birth to the AR-15. The AR-10 is a gas-operated rifle that produces a manageable recoil. Also, its accuracy level is commendable.
Unlike AR-15s, AR-10 parts are not standardized; thus, you are strictly restrained to the DPMS series and ArmaLite series. The two brands have interchangeable parts. However, it’s good for anyone intending to build an AR-10 e aware that most internal parts are not compatible.
What parts do you need to build an AR-10 rifle? How do you build an AR-10? This article has all the details to answer these questions.
Parts of an AR-10 Needed for a Build
- Lower Receiver
- Bolt Carrier Group
- Forward Assist Assembly
- Recoil Spring
- Gas piston
- Upper Receiver
- Sights (front & rear)
- Gas tube
- Ejection Port Cover Assembly
- Muzzle Devices
- Charging Handle
- Gas Block & Gas Valve
Note: The Lower Receiver and Upper Receiver may be in a pre-assembled form or individual components that you will need to assemble yourself.
Here is a list of components that make up the Lower Receiver:
- Magazine Catch Assembly
- Bolt Catch Assembly
- Safety Selector Assembly
- Latch Plate
- Castle Nut
- Buffer and Buffer Tube
- Fire Control Group
- Pivot pin
- Front and Rear Takedown pins, springs, and detents
Essential Tools Needed
- Armorer’s Wrench
- Punch Set
- Allen Keys
- A pair of pliers
- Pivot Pin installation tool
A Step-by-Step Guide to Build an AR-10
In our guide, we shall use individual components to build up the AR-10. Let’s get started.
AR-10 Lower Receiver Assembly
- The first thing will entail assembling the AR-10 lower receiver.
- Start by placing the Spring and the Detent into the holes located at the front-end of the receiver.
- Then roll in the Pivot Pin vertically into the two holes on the end of the receiver. However, ensure the canal of the Pivot Pin is well aligned with the Detent.
- It’s time to install your Magazine Catch Assembly.
- First, insert the Magazine Catch into the Receiver. Then the Magazine Spring comes next, and it’s installed from the other side of the Receiver. Finally, drive in the Magazine Release Button on the threaded end of the Magazine Catch.
- Ensure the above assembly is well fitted into the receiver before you proceed to install the Bolt Catch Assembly.
- Start by placing a Roll Pin Flush into the Bolt Catch slot. Position the Bolt Catch Plunger and the Spring into their respective holes.
- Then slide in the Bolt Catch into its slot, not forgetting to ensure a nice alignment with the holes.
- Use a plastic Mallet Hammer to drive in the Roll Pin completely.
- Proceed and work on your Fire Control Group
- Position your Spring onto the Trigger and further insert your Disconnector Spring into the canal of the Trigger.
- Drop in the Trigger into the Receiver and align it with the Trigger Pinhole. It allows pushing in the Trigger Pin through the Disconnector.
- Now attach the Spring to the Hammer. However, you will need to pull back the Hammer to allows space to push back the Selector in position.
- Fix the pistol grip onto the receiver.
- Insert a Selector Spring and a Selector Detent into the top hole of the Pistol Grip.
- Place the Takedown Springs and Detent into the hole right next to the Selector Detent.
- Ensure your Grip is well aligned in its slot. Also, tighten it using bolts and washers in the respective holes.
- Check whether the Safety and Takedown pin functions well.
- It’s time you install your Buffer Tube.
- Then use a Punch and a hammer to punch in the Steel Castle Nut into the recess.
- Fit in the stock into the buffer tube.
- Now, that’s a milestone because you have a fully assembled AR-10 Upper Receiver.
AR-10 Upper Receiver Assembly
Here is a precise guide on how to assemble your Upper Receiver
- Start inserting the Forward Assist and its Spring into the respective slot in the Upper Receiver. Also, apply enough pressure on the Forward Assist till you drop in the Forward Assist Roll Pin.
- The next step entails the installation of the Ejection Port Cover Assembly.
- At this stage, you need to pay attention to the Ejection Port Cover Spring. You need to twist the long side of the Spring at 360 degrees in order to create tension that helps it fit in the Ejection Port Door.
- Ensure the Ejection Port Cover, the Spring, and the holes on the Lower Receiver align properly before driving in the Cover Pin.
- Another step is setting up the Barrel on the Lower Receiver.
- However, you should apply some grease on the threaded end of the Receiver and the Barrel.
- Align the small knob on the rear end of the Barrel to the front part of the Lower Receiver.
- Then fit in the Barrel Nut to join the Barrel to the Receiver on the Receiver’s threaded end. It’s good to use a Torque Wrench and a Barrel Extension to tighten the Barrel effectively.
- Now position your Gas Tube and Gas Block into the Receiver. One end of the gas tube fits nicely on the gas block while the other should go into the Lower Receiver.
- Ensure your Gas Block is well tightened on the Barrel.
- Proceed and install your handguard. Ensure you a perfect alignment of the handguard on the platform before tightening it with some screws.
- Insert a Crush Washer on the front part of the Barrel.
- Now, position your muzzle device on the same spot of the Barrel.
- Next, insert the charging handle and then align the Gas Key to the canal underneath the Charging Handle.
- At this stage, you have achieved another milestone: you have a complete Lower Receiver.
Other steps of the building process
- With a complete Upper Receiver Assembly and Lower Receiver Assembly, you should join them together.
- You should then add other accessories such as sights, scopes, and light on your rifle’s handguard.
- Ensure that everything on your AR-10 is well tightened and aligned.
- Feed the AR-10 with a magazine that has the appropriate ammunition for a particular caliber.
- Go to a shooting range near you for a test.
The process of building an AR-10 is not complicated when you have the right tools and parts. Also, it similar to that of building an AR-15. When your AR-10 rifle is well configured, it will offer you an exceptional experience whenever you fire.