F1 Firearms AR-15 Gun Builders Lower Parts Kit

Comprehensive Lower Parts Kit for AR-15 Builds

The F1 Firearms AR-15 Gun Builders Lower Parts Kit is engineered to provide everything you need to complete or upgrade the lower receiver of your AR-15 rifle. Crafted from high-grade materials and finished in durable black to resist corrosion, this kit brings Mil-Spec quality to your next build. Whether you are a first-time builder or a seasoned gunsmith, you will appreciate the precise tolerances, consistent performance, and reliable function these parts deliver when assembled into any standard AR-15 lower receiver.

Precision Machined Components for Durable Performance

Every component in this lower parts kit is machined to exacting standards for a smooth fit and superior durability. From the hardened steel bolt catch to the polished magazine catch spring, each piece is designed to work together without binding or premature wear. The buffer retainer and buffer retainer spring are engineered to maintain proper buffer tension under heavy firing cycles, while the selector detents and springs provide a crisp, audible click when toggling between safe and fire positions.

Complete Kit Contents

This all-inclusive kit contains every essential part required to assemble a fully functional AR-15 lower receiver. You will receive:

• 1 Bolt Catch
• 1 Bolt Catch Spring
• 1 Bolt Catch Plunger and Screw
• 1 Magazine Catch
• 1 Magazine Catch Spring and Button
• 2 Trigger Pins
• 1 Pivot Pin and 1 Takedown Pin with Detents
• 1 Buffer Retainer and 1 Buffer Retainer Spring
• 1 Selector Hard Detent, 1 Selector Soft Detent, and 1 Selector Detent Spring
• 1 Receiver Pivot Detent Spring and 1 Takedown Detent Spring
• 1 Safety Selector Assembly (Long Paddle, Short Paddle, Tumbler, and 2 Screws)

Easy Installation and Mil-Spec Compatibility

Designed for compatibility with all Mil-Spec AR-15 lower receivers, this builder’s kit installs quickly with basic bench-built tools. Detailed instructions are available online to guide you through each step, from inserting detents to securing the safety selector. Clearances are optimized to eliminate excessive play while avoiding tight fits that cause installation headaches. The end result is a low-profile, rock-solid lower assembly ready for your choice of upper receiver.

Enhanced Reliability and Consistency

Reliability is the cornerstone of any high-performance AR-15 build. F1 Firearms achieves consistent cycling and crisp trigger resets through precision springs and hardened detents engineered to withstand thousands of rounds. The magazine catch spring and buffer retainer spring are heat-treated for maximum longevity, ensuring your rifle maintains peak performance during extended use or competition firing sequences.

Unmatched Value for Budget-Conscious Builders

While many lower parts kits sacrifice quality for cost, the F1 Firearms AR-15 Builder’s Kit strikes the perfect balance of affordability and durability. Priced competitively at just 94.99, this kit rivals premium brands at a fraction of the cost. By choosing F1 Firearms, you invest in a trusted name known for attention to detail, rigorous quality control, and excellent customer support.

Ideal for Customization and Upgrades

Whether you are upgrading a factory AR-15 or starting from scratch, this lower parts kit accommodates aftermarket triggers, grips, and stocks. The selector paddles allow you to choose between long and short styles based on personal preference or ambidextrous setups. Combine this kit with your preferred trigger group and buffer assembly to tailor the feel and function of your rifle.

Trusted Brand Backed by F1 Firearms

F1 Firearms has built a reputation for delivering quality firearms and components to shooting enthusiasts and professionals. Every kit is inspected before shipping to ensure complete accuracy and performance. In the rare event of a missing or defective part, F1 Firearms’ dedicated customer service team will resolve any issues promptly so you can get back to the range without delay.

Order Your Lower Parts Kit Today

Upgrade your AR-15 build with confidence—add the F1 Firearms AR-15 Gun Builders Lower Parts Kit to your cart now. With complete Mil-Spec compatibility, premium materials, and a full complement of components, this is the smart choice for reliable, long-lasting performance. Don’t settle for less when you can build with the best. Shop today and experience the F1 Firearms difference.