How to Build an AR-15 on a Budget
Woody's answers are based on published federal and state law. Not legal advice. Consult a licensed attorney for your specific situation.
Focus on bare-bones essentials: polymer lower, basic trigger group, carbine buffer system, and mil-spec BCG. Skip upgrades like fancy triggers, rails, or optics until the rifle functions reliably.
How This Affects Your Build
Building a budget AR-15 requires prioritizing function over features while avoiding components that compromise reliability. The modular design allows you to upgrade incrementally over time. Starting with proven, basic components establishes a solid foundation that won't leave you with an expensive paperweight.
The Detail
Start with a stripped lower receiver from any reputable manufacturer since they're all built to the same mil-spec dimensions. Polymer lowers can save significant money over aluminum without sacrificing reliability for most applications. Complete the lower with a basic mil-spec trigger group, standard trigger guard, and basic grip and stock.
For the upper assembly, focus on getting a complete upper receiver group rather than building piece by piece. This typically costs less than sourcing individual components and ensures proper headspacing and assembly. Look for carbine-length gas systems with standard handguards rather than free-floating rails. The carbine system is forgiving and reliable, while basic handguards are perfectly functional for most shooting.
Your bolt carrier group should be properly staked, shot-peened, and magnetic particle inspected, but doesn't need fancy coatings or exotic materials. A standard mil-spec BCG from established manufacturers will serve you well. Similarly, stick with a standard carbine buffer system rather than adjustable options that add complexity and cost.
Avoid the temptation to immediately add accessories like upgraded triggers, optics, or tactical furniture. These can easily double or triple your build cost while adding minimal functional benefit to a basic rifle. Focus your budget on reliable core components that ensure the rifle cycles properly and shoots accurately.
Build Impact
This approach typically results in a functional AR-15 for significantly less than premium builds while maintaining reliability. You can always upgrade components later as your needs and budget allow, making this strategy both economical and practical for new builders.