The Fundamentals of Building a Rifle

See what it takes to build a rifle

While you can certainly buy a pre-built rifle, like the popular AR-15 platform, you can also build your own. Now, this is not like a video game where you slap together whatever you want and make it look completely unrealistic. Insead, building a rifle is a project that combines technical skill, a deep understanding of firearms, and adherence to legal regulations. Whether motivated by a desire for customization, personal satisfaction, or cost-effectiveness, many firearm enthusiasts choose to build their own rifles. But how do you actually go about putting together your own rifle and making sure that it works properly?

This article will walk you through the process, discuss the legal considerations, and explore the pros and cons of building a rifle. Let’s dive in. 

Steps to Building a Rifle

build a rifle

There are a few different steps to building a rifle. Let’s take a look at each of them.

Research and Planning

  • Purpose: Define the purpose of the rifle as there are several different reasons that you might be in the market. For example hunting, sport shooting, and home defense are some of the most popular.
  • Type: Choose the type of rifle. Some of the most popular rifles that you will see being built are AR platforms, but you can stray from that and build lever actions, bolt actions, and so on.
  • Specifications: Determine the specifications such as caliber, barrel length, stock type, and optics (iron sights, scopes, etc.)

Acquiring Parts and Tools

  • Parts: Purchase the necessary parts in order to make sure that the rifle functions properly, including the lower receiver, upper receiver, barrel, stock, trigger assembly, handguard, and other components. The lower receiver is the key part legally considered a firearm.
  • Tools: Ensure you have the required tools to put everything together, as sometimes the pieces that a rifle uses are not your average screws. Some tools you may need can include a vise, torque wrench, armorer’s wrench, punch set, and a workbench.

Assembly Process

  • Lower Receiver Assembly:
    • Install the trigger group, hammer, and safety selector.
    • Attach the buffer tube, buffer spring, and stock.
  • Upper Receiver Assembly:
    • Mount the barrel to the upper receiver using a barrel nut.
    • Install the gas system (gas block and gas tube).
    • Attach the handguard.
    • Install the bolt carrier group and charging handle.
  • Final Assembly:
    • Join the upper and lower receivers using takedown pins.
    • Install any additional accessories such as optics, sights, and sling mounts.

Testing and Adjustment

  • Function Check: Perform a thorough function check to ensure all parts operate correctly. This should be done without any ammunition in the firearm and in a safe area, not necessarily in the house.
  • Range Test: Test fire the rifle at a shooting range to verify functionality and make necessary adjustments to the sights or optics, and well, to make sure the rifle you built doesn’t just blow up in your hands. 

Legal Considerations When Building a Rifle

Building a rifle is legal in many parts of the United States, but strict regulations must be followed in some states. Let’s take a look at some of the laws surrounding building a rifle.

  1. Federal Laws:
    • Lower Receiver: The lower receiver is the regulated part of the firearm. Purchasing a lower receiver requires going through a Federal Firearms License (FFL) dealer, involving a background check, you can’t just order a lower receiver online and have it shipped to your door.
    • Serial Numbers: Homemade firearms do not need a serial number if kept for personal use, but it is recommended to serialize them for identification purposes.
  2. State Laws:
    • Varies by State: Some states have additional regulations, including restrictions on certain types of firearms, magazine capacities, and required registrations.
    • Assault Weapons Bans: States like California, New York, and others have specific bans on so-called "assault weapons," which may affect the legality of certain builds.
  3. Prohibited Persons:
    • Background Checks: Individuals prohibited from owning firearms (due to felony convictions, domestic violence restraining orders, etc.) cannot legally build a firearm.

Pros and Cons of Building a Rifle

rifle build

There are a few different pros and cons to building a rifle when it comes to comparing building vs. buying.


  1. Customization: Building your rifle allows for full customization, from choosing specific components to personalizing the look and feel. Again, it is not a video game where you can just slap on whatever you want, but you can get pretty creative with your rifle build.
  2. Cost Savings: Building a rifle allows you to potentially save money compared to buying a pre-assembled rifle, especially if you source parts smartly.
  3. Knowledge and Skills: Being that building a rifle requires you to learn the firearm quite literally inside and out, building a rifle helps to gain a deeper understanding of firearm mechanics and develop valuable gunsmithing skills.
  4. Performance Optimization: Tailor the rifle to your specific needs, ensuring optimal performance for your intended use.


  1. Legal Risks: Navigating the complex web of federal and state regulations can be challenging and mistakes can lead to legal trouble, which is something that no one wants to deal with.
  2. Initial Costs: The upfront investment in tools and parts can be significant, particularly for high-quality components. 
  3. Time and Effort: Building a rifle is time-consuming and requires patience and attention to detail, and this is something that will turn many people off and make them want to just buy a pre-built rifle.
  4. Technical Challenges: Without proper knowledge and experience, you might encounter difficulties during the assembly process, potentially leading to safety issues.

Should You Build or Buy a Rifle?

There are plenty of factors that go into both building and buying a rifle. For one, a pre-built rifle will more than likely have a warranty, it is already assembled, and it may be put together better than you can do. However, a pre-built rifle may not have the customization that you want, and it also may be at a higher price point.

Ultimately, the choice is yours to make, and depends on personal preferences, budget, and a few other factors.


Building a rifle can be a rewarding experience that offers a high degree of personalization and a sense of accomplishment. However, it requires careful planning, a thorough understanding of legal requirements, and a willingness to invest time and resources. By weighing the pros and cons and adhering to all legal guidelines, firearm enthusiasts can successfully build a rifle tailored to their specific needs and preferences.

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