Blogs & Articles

Tips for a smooth AR15 assembly process

The AR15 is a popular rifle among gun enthusiasts, known for its versatility and customization options. Whether you are building your AR15 from scratch or upgrading your current rifle, the assembly process can be daunting for beginners. In this article, we will provide tips for a smooth AR15 assembly process to help you build your dream rifle.

Understanding the AR15 Parts

Before diving into the assembly process, it is essential to understand the different parts of an AR15. The AR15 consists of a lower receiver, upper receiver, barrel, bolt carrier group, buffer tube, and stock. Each of these parts plays a crucial role in the function of the rifle, and it is essential to have a basic understanding of their functions before beginning the assembly process.

Lower Receiver

The lower receiver is the main component of the AR15 and is considered the firearm by the ATF. It houses the trigger, magazine well, and controls the firing mechanism of the rifle.

Upper Receiver

The upper receiver is the top portion of the AR15 and houses the bolt carrier group and barrel. It is responsible for chambering and ejecting rounds.


The barrel is the long, cylindrical metal tube that the bullet travels through when fired. It is essential to choose the right barrel length and caliber for your intended use of the rifle.

Bolt Carrier Group

The bolt carrier group is responsible for loading, firing, and ejecting rounds. It consists of the bolt, bolt carrier, and firing pin.

Buffer Tube and Stock

The buffer tube and stock are located at the rear of the AR15 and provide support and stability when firing. The buffer tube houses the buffer and recoil spring, while the stock is where the shooter rests their cheek when aiming.

Gather the Necessary Tools

Before beginning the assembly process, it is crucial to have all the necessary tools on hand. This will save you time and frustration in the long run. Some essential tools for AR15 assembly include:

  • Armorers wrench
  • Punch set
  • Vise block
  • Torque wrench
  • Hammer
  • Screwdriver set
  • Roll pin punch set
  • AR15 vice block
  • AR15 lower receiver vice block

Start with the Lower Receiver

AR15 lower receiver


The lower receiver is the foundation of the AR15, and it is recommended to start the assembly process with this component. Begin by installing the trigger, hammer, and safety selector. Next, insert the magazine catch and bolt catch. It is essential to pay attention to the orientation of these parts to ensure proper function.

Once these components are installed, it is time to install the buffer tube and stock. This process can be tricky, so it is recommended to use a vice block to hold the lower receiver in place. Begin by installing the buffer tube and then attach the stock. Make sure to tighten the castle nut to the proper torque specification.

Assemble the Upper Receiver

The upper receiver assembly process is relatively straightforward. Begin by installing the forward assist and ejection port cover. Next, attach the barrel to the upper receiver using the barrel nut and torque wrench. It is crucial to follow the manufacturer’s torque specifications to ensure proper function.

Once the barrel is attached, insert the bolt carrier group into the upper receiver. Make sure to lubricate all moving parts before installation. Finally, attach the charging handle and handguard to complete the upper receiver assembly.

Attach the Upper and Lower Receivers

AR15 upper and lower receivers

by Josh Miller (

With both the upper and lower receivers assembled, it is time to attach them. Begin by inserting the takedown and pivot pins to secure the upper and lower receivers together. It is essential to ensure that the pins are fully inserted and locked in place.

Test Fire and Make Adjustments

Once the AR15 is fully assembled, it is crucial to test fire the rifle and make any necessary adjustments. This includes checking the trigger pull, ensuring proper function of the bolt carrier group, and adjusting the sights if necessary.

Tips for a Smooth Assembly Process

Assembling an AR15 can be a challenging and time-consuming process, especially for beginners. Here are some additional tips to help make the assembly process smoother:

Follow the Manufacturer’s Instructions

Every AR15 is different, and it is crucial to follow the manufacturer’s instructions for your specific rifle. This includes torque specifications, proper lubrication, and any other specific instructions.

Take Your Time

Rushing through the assembly process can lead to mistakes and frustration. Take your time and double-check your work to ensure everything is installed correctly.

Use the Right Tools

Using the proper tools for AR15 assembly will make the process much smoother. It is worth investing in quality tools to ensure a successful build.

Seek Professional Help if Needed

If you are struggling with the assembly process, do not hesitate to seek professional help. Many gun shops offer assembly services, and it is better to have a professional complete the build than to risk damaging your rifle.


Building an AR15 can be a rewarding experience, but it is essential to have a basic understanding of the rifle’s parts and the necessary tools before beginning the assembly process. By following these tips and taking your time, you can build a high-quality AR15 that meets your specific needs and preferences. Remember to always follow safety precautions and seek professional help if needed. Happy building!

Stay Updated with

Our Newsletter

Recent Posts