Building an AR-15 is a rewarding project for firearm enthusiasts, but it can also be an expensive endeavor—especially if you’re purchasing a fully assembled rifle or high-end components. That’s where 80 lower come in. Starting your build with an 80 lower receiver is not only cost-effective but also gives you greater control over how you allocate your budget.
In this guide, we’ll explore how starting with an 80 lower receiver can save you money, offer customization options, and help you build a high-quality AR-15 on a budget.
What Is an 80% Lower Receiver?
An 80% lower receiver is a partially machined lower receiver that requires additional work before it can be used as the core component of an AR15. Since it’s unfinished, it’s not classified as a firearm under federal law, making it a budget-friendly entry point for builders.
Why Choose an 80 Lower?
- Lower Cost: Unfinished lowers are significantly cheaper than fully assembled or serialized lower receivers.
- DIY Advantage: You can complete the lower yourself, saving on manufacturing and assembly costs.
- Customization Freedom: Start with a blank slate and prioritize where to spend your money.
How Does Starting with an 80 Lower Save You Money?
1. Cheaper Initial Cost
An 80% lower receiver is typically much more affordable than a serialized or fully assembled lower.
- Example: A high-quality 80 lower might cost $50–$100, while a fully assembled lower can easily exceed $200.
- Savings Opportunity: Use the money saved on the lower to invest in premium components like the barrel, trigger, or optics.
2. No FFL Fees
Because 80 lowers are not classified as firearms, they can be purchased without the need for a Federal Firearms License (FFL) transfer.
Typical FFL Costs:
- Background check fees: $20–$50.
- Transfer fees: $25–$75.
By skipping the FFL process, you can put that money back into your build.
3. Avoid Overpaying for Features You Don’t Want
Prebuilt lowers often come with standard components that may not suit your needs. You’ll end up replacing parts like the stock, trigger, or pistol grip, effectively paying twice.
With an 80 Lower:
- Start with a blank canvas and only pay for the parts you want.
- Focus your budget on essential components rather than wasting money on unnecessary upgrades.
4. Gradual Investment
When building from an 80 lower, you have the flexibility to buy parts over time rather than making a large upfront purchase.
Budget Benefits:
- Spread out costs by purchasing components as your budget allows.
- Take advantage of sales or discounts on parts to save even more.
How to Build an AR-15 on a Budget with an 80 Lower
Step 1: Start with a Quality 80 Lower Receiver
Choose a reliable 80 lower that meets your needs. Aluminum lowers (7075-T6 or 6061-T6) are durable and versatile, while polymer lowers are lightweight and more affordable.
Average Cost:
- Aluminum: $60–$100.
- Polymer: $50–$80.
Step 2: Invest in a Jig Kit and Tools
Completing an 80 lower requires a jig kit and basic machining tools. While this may seem like an upfront expense, these tools can be reused for future builds, saving money in the long run.
Jig Kit Options:
- Budget-Friendly Kits: $50–$100.
- Premium Kits: $150–$300 (includes drill bits and end mills).
Tools You’ll Need:
- Router or drill press.
- Vise for securing the jig.
- Safety equipment (gloves, goggles, etc.).
Step 3: Prioritize Your Spending
Focus your budget on the components that will have the most impact on performance:
Key Components to Prioritize:
- Barrel: Invest in a high-quality barrel for accuracy and reliability.
- Cost: $100–$300.
- Bolt Carrier Group (BCG): A premium BCG ensures smooth cycling and durability.
- Cost: $100–$200.
- Trigger: Upgrading to a premium trigger can improve accuracy and shooting experience.
- Cost: $50–$150.
Step 4: Choose Cost-Effective Components
Look for affordable but reliable options for less critical parts:
- Handguards: Budget-friendly M-LOK or Picatinny rails.
- Cost: $30–$100.
- Stock: Adjustable stocks offer versatility without breaking the bank.
- Cost: $30–$80.
- Lower Parts Kit (LPK): Includes the fire control group and small components.
- Cost: $40–$100.
Step 5: Assemble It Yourself
Assembling your AR-15 yourself saves you money on labor costs and gives you valuable hands-on experience. Online tutorials and guides can walk you through the process step by step.
Benefits of Building an AR-15 with an 80 Lower
1. Learn Valuable Skills
Completing an 80% lower and assembling your AR-15 teaches you how the firearm works, making it easier to troubleshoot and maintain.
2. Tailor It to Your Needs
Building from scratch ensures every component fits your intended purpose, whether it’s for home defense, hunting, or competition.
3. Stay Under Budget
By focusing on essentials and skipping unnecessary features, you can build a high-quality AR-15 for less than the cost of a prebuilt rifle.
Example Budget Build
Here’s a sample budget for building an AR-15 using an 80 lower receiver:
| Component | Estimated Cost |
| 80% Lower Receiver | $80 |
| Jig Kit and Tools | $150 (reusable) |
| Barrel | $150 |
| Bolt Carrier Group (BCG) | $120 |
| Lower Parts Kit (LPK) | $50 |
| Handguard | $50 |
| Stock | $40 |
| Total Cost | $640 |
Compare this to the $1,000+ price tag of many prebuilt rifles, and it’s clear how starting with an 80 lower can save you money.
Final Thoughts
Building an AR-15 on a budget doesn’t mean sacrificing quality. By starting with an 80% lower receiver, you can create a custom firearm tailored to your needs while saving money on unnecessary features and FFL fees.
Ready to start your build? Check out Thunder Tactical for high-quality 80% lowers, jig kits, and all the components you need to build a budget-friendly AR-15 that performs like a premium rifle. Happy building!