Originally posted here.
Whether you’re building a new AR or upgrading an existing one, one of the pivotal choices you’ll face is selecting the right lower receiver.
With the AR-15 and AR-10’s rich history spanning several generations, it’s not surprising that the market is flooded with a plethora of options, from the classic MIL-SPEC designs to more contemporary, ambidextrous, and aesthetically pleasing ones.
Choosing the right lower receiver is a balance between manufacturing, materials, and weight considerations tailored to your budget and functional needs.
In this article, not only will we dive into the evolution and intricacies of AR lower receivers, but we’ll also spotlight some of the top choices that Faxon Firearms is bringing to the market.
Whether you’re a first-time builder, looking to upgrade, or simply aiming to expand your knowledge, we’ve got you covered.
Different Lower Receiver Materials
When looking into the various lower receiver materials, three predominant types emerge: cast aluminum, billet aluminum, and forged aluminum.
The cast aluminum manufacturing process is a straightforward method. It involves pouring molten aluminum into a mold, allowing it to cool, resulting in a lower receiver that is then subjected to final machining.
Because the aluminum is initially in liquid form during casting, the resulting product exhibits a relatively loose crystalline structure. This crystalline structure makes it the least robust among the three primary aluminum processing methods.
Nevertheless, it’s important to note that even though cast aluminum is considered the weakest of the three options, it still provides ample strength for the lower receiver to function safely and reliably without any concerns of malfunction. However, in terms of preference, it is generally considered the least favorable of the available manufacturing processes for aluminum components.
When it comes to billet aluminum lower receivers, the process begins with a solid block of pure aluminum, akin to a sculptor starting with a block of marble. This aluminum block undergoes various precision machining operations, transforming it into a meticulously finished product.
Working with billet aluminum is like sculpting with metal, and this process offers distinct advantages over casting. Billet lowers are inherently stronger due to their solid composition, and they exhibit a finer finish.
For those seeking to create a firearm with a distinct appearance, billet lower receivers are an excellent choice. They offer significant customization potential from the outset, making it possible for manufacturers to craft unique features such as skull-shaped magazine wells, integrated trigger guards, and additional machining for weight reduction.
The production of billet lower receivers involves CNC (Computer Numerical Control) machining, wherein a solid block of aluminum is meticulously sculpted by automated precision equipment. This CNC-driven process enables intricate and highly customized designs that cater to individual preferences.
Although billet lowers tend to come with a higher price tag, they are cherished by many for their versatility and aesthetic appeal. These receivers are crafted from billeted chunks of aluminum exposed to CNC machinery, allowing for sharp lines and the creation of striking, unique looks. Some enthusiasts even take it to the extreme in terms of design.
It’s worth noting that while billet lowers are considered “weaker” compared to forged lowers, this distinction is rarely noticeable to the user. They maintain excellent durability and won’t crack or break prematurely. However, some of the more unique billet lowers may have compatibility limitations, so it’s essential to verify their compatibility with MIL-SPEC parts, particularly if you plan to pair them with a specific billet upper receiver.
Among the three primary types, forged aluminum lower receivers stand out as the strongest and most prevalent option. This process essentially involves subjecting aluminum to a vigorous transformation, molding it through mechanical force.
In the forging process, machinery exerts immense pressure on a block of aluminum to shape it into the desired configuration, followed by precision machining to refine the receiver’s form. The compression endured by the aluminum during forging significantly enhances its structural integrity.
Forged lower receivers excel when you require an AR-15 that will see frequent use and may be carried around extensively. Their key attributes include strength, durability, and a commendable lightweight design.
The production of forged lower receivers entails hammering a block of aluminum into its final shape. This method ensures the creation of a receiver that not only boasts robustness but also remains lightweight and durable. It’s no surprise that forged lower receivers are a preferred choice among gun enthusiasts for their AR-15 builds.
In fact, the majority of lower receivers in circulation are forged. The forging process entails the transformation of a chunk of aluminum through precision hammering, sculpting it into the distinctive form of an AR-15 lower. Following the forging, a CNC machine is employed to further refine the receiver’s contours, after which it undergoes a meticulous cleaning process before the application of its final finish.
While forged lowers are renowned for their superior strength, it’s worth noting that this added strength is typically not perceptible in regular usage. Their status as the industry standard ensures widespread compatibility with aftermarket components. Due to their prevalence and mass production, forged lowers are often available at more budget-friendly prices.
What is 7075-T6 Aluminum?
In the realm of aluminum alloys commonly used for lower receivers, two prominent choices stand out: 6061-T6 and 7075-T6.
The fundamental disparity between them boils down to two crucial factors: strength and corrosion resistance.
7075-T6, distinguished by its exceptional strength, outperforms 6061-T6 in this regard by nearly doubling its strength characteristics. Naturally, this disparity in strength does translate to a difference in cost, with 7075-T6 typically being the more expensive option.
However, it’s important to note that 6061-T6 exhibits superior corrosion resistance when compared to its counterpart. This corrosion resistance is a notable advantage, although its significance may vary depending on whether your receiver is left in its bare aluminum state or subjected to surface finishing treatments.
When strategizing your firearm build, it’s prudent to weigh the importance of enhanced strength against cost considerations. In today’s context, the difference between 7075 and 6061 is relatively minimal. Still, many enthusiasts prefer the peace of mind that accompanies the robustness of 7075-T6, making it their preferred choice.
Additionally, it’s worth mentioning that 7075-T6 aluminum is commonly employed in aerospace applications due to its exceptional strength-to-weight ratio and toughness, underscoring its reputation for durability and reliability.
Complete Lower vs Stripped Lower
If you’re venturing into your first firearm build, you’ve likely encountered two distinct options for lower receivers: stripped and complete. The question that naturally arises is, “What sets them apart, and which one should I opt for?” Let’s delve into a comparison to help you make an informed choice.
Stripped Lower Receivers
When you come across stripped lower receivers, you might wonder if something essential is amiss. Indeed, with stripped lowers, critical components necessary for assembling a fully functional lower receiver are absent. These components include the trigger, buffer tube, buffer, and stock.
But why would you consider purchasing a stripped lower receiver when it lacks so many integral parts?
- Greater Customization: Stripped lower receivers provide an unparalleled level of customization. You have the freedom to meticulously select each component, tailoring your receiver precisely to your preferences.
- Cost-Effective: Stripped lower receivers often come at a lower price point than complete counterparts, making them a prudent choice if budget considerations come into play.
- Enhanced Understanding: Building a stripped lower receiver demands a deeper understanding of the mechanical aspects of your rifle. It’s an excellent opportunity for learning and gaining insight into the inner workings of your firearm.
However, there are some downsides to choosing stripped lower receivers:
- More Labor-Intensive: Constructing a stripped lower receiver involves a substantial investment of time and effort, as each part must be meticulously fitted and installed.
- Additional Tools Required: Building a stripped lower receiver necessitates essential tools like punches and wrenches, which may not be readily available to all enthusiasts.
- Technical Knowledge Needed: Assembling a stripped lower receiver demands a certain level of technical knowledge and expertise, which might not be easily accessible to all gun enthusiasts.
Complete Lower Receivers
Conversely, complete lower receivers come equipped with all the necessary components essential for creating a fully functional lower receiver. If you opt for a complete lower receiver, the only additional component you’ll require to assemble a functioning rifle is the upper receiver. Simply attach the complete upper receiver to the complete lower receiver, and your firearm is ready to go.
Here are the advantages of purchasing a complete lower receiver:
- Convenience: Complete lower receivers offer unmatched convenience, particularly for those who lack the time, expertise, or tools to assemble a stripped lower receiver.
- Time-Saving: Since all components come pre-assembled, complete lower receivers save significant time and effort compared to building a stripped lower receiver from scratch.
- Guaranteed Compatibility: All components in a complete lower receiver are meticulously designed to work harmoniously together, eliminating concerns about compatibility issues.
However, there are some drawbacks to consider:
- Reduced Customization: Complete lower receivers come pre-assembled, limiting your control over individual parts compared to a stripped lower receiver.
- Higher Cost: Convenience and pre-assembled components come at a price, making complete lower receivers generally more expensive.
- Limited Learning Opportunities: Since a complete lower receiver is already assembled, you’ll have fewer opportunities to gain hands-on knowledge about your firearm’s inner workings.
In essence, your choice between stripped and complete lower receivers hinges on your preferences, skill level, and the level of customization and understanding you seek in your firearm build.
Best AR Lower Receiver Sets
Among the myriad of options available in the market, the Faxon AR lower receivers consistently stand out as a top choice for enthusiasts and professionals alike.
Faxon X-Tra Lite AR-15 Receiver Set – Upper & Lower, stripped, Anodized
The Faxon HyperLite AR-15 Receiver Kit is the foundational piece you’ve been searching for to embark on your next lightweight build. Drawing inspiration from our widely acclaimed forged receiver set, this kit accentuates the design, focusing not just on form but also on function and durability, all the while ensuring a marked decrease in both mass and weight.
Weighing in at just .96 lbs. when paired with an ejection port and dust cover, this receiver kit is a testament to precision engineering and innovative design. Notably, it’s 2.08 ounces lighter than our standard forged receiver set, making it a top choice for those who value efficiency without compromising on quality.
Each HyperLite Receiver Kit is meticulously trued by our skilled team right here in our Greater Cincinnati, Ohio facility. We’ve honed the inner bore to enhance the action of the bolt carrier group, ensuring smoother operations and a more fluid user experience. For those who seek a sleeker, more streamlined look and feel, we’ve opted to delete the forward assist.
When it comes to detailing, the skeletonized Picatinny Rail stands out, not just for its weight-reducing design, but also for the manually engraved T-marks that add a touch of precision and craftsmanship. The skeletonized shell deflector is another feature that further reduces the overall weight while maintaining structural integrity. Furthermore, we’ve instilled tighter tolerance on the lugs, ensuring a better, more snug fitment for optimal performance.
While the kit ships unassembled, it offers a unique opportunity for enthusiasts to truly make it their own. The aesthetic milling of the upper is pleasing to the eye and practical, showcasing Faxon’s heritage “X” logo, which also serves the dual purpose of decreasing material and mass. Additionally, the Faxon “X” skeletonized magwell is more than just a branding statement; it’s another step in our commitment to further reducing mass without cutting corners.
The Faxon HyperLite AR-15 Receiver Kit is the perfect blend of aesthetics, functionality, and cutting-edge design. It’s an investment in quality and performance, ideal for those who want the best for their build.
*Also available in OD Green Cerakote, Titanium Cerakote, and Midnight Bronze
Faxon Billet AR-10 Receiver Set – Upper & Lower, Stripped, Anodized Black
The Faxon Billet AR-10 Receiver Set is not just another component in the firearms market; it’s a testament to precision engineering and dedication to unparalleled quality. Designed for serious enthusiasts, this receiver set is a comprehensive solution for those looking to significantly upgrade their AR-10 rifle.
Every piece of this set, which comprises a stripped upper and lower receiver, is forged from a superior 7075-T6 aluminum billet. This premium material selection ensures that while the receiver set remains lightweight, it does not compromise on strength. Such a design is primed to endure heavy use, ensuring long-lasting reliability and resilience.
Faxon’s commitment to excellence is evident in the unique design elements incorporated into this receiver set. The integrated trigger guard adds to the aesthetic appeal and ensures safety and improved ergonomics. The flared magwell aids in faster and more efficient magazine changes, enhancing the rifle’s functionality during rapid-fire scenarios. Additionally, a special tensioning screw has been included to facilitate a snug fit between the upper and lower receivers. This tight fit is instrumental in enhancing accuracy, ensuring the rifle’s components move in perfect harmony.
Now, diving deeper into the specifics:
- Crafted from 7075-T6 Billet Aluminum, it promises strength without added weight.
- It comes with a Type III Class 2 Hard Coat Black Anodized finish, adding to its resilience and giving it a sleek appearance.
- Designed to meet the DPMS High Profile standards, ensuring compatibility with a range of components.
- Also constructed from high-grade 7075-T6 Billet Aluminum.
- Features the Type III Class 2 Hard Coat Black Anodized finish, consistent with the upper receiver.
- Enhanced features such as an Extended Mag Catch Button, a Threaded Bolt Catch Pin, and a Rear Takedown Detent Spring Retained with a Set Screw. An Upper Receiver Tension Screw is also provided.
- Includes a Right Side Bolt Release Lever made of 4140 and treated with Blacknitride+™ for enhanced durability.
- While it’s marked with a “MULTI” caliber designation, it’s designed to accept a variety of calibers, namely .308 Winchester (7.62x51mm NATO), 8.6 Blackout, .243 Winchester, 6.5 Creedmoor, .260 Remington, and .338 Federal. This flexibility allows users to tailor their firearms to specific needs and preferences.
What further sets the Faxon Billet AR-10 Receiver Set apart from the competition is the trust instilled by the Faxon Lifetime Guarantee.
This ensures that any potential defects in materials or workmanship are covered for the lifetime of the product. As a user, this not only secures your investment but provides invaluable peace of mind.
Limited Edition Faxon 9″ AR-15 Builder Set – FDE
The Limited Edition Faxon AR-15 Builder Set is a game-changer for firearm enthusiasts. This meticulously designed set is not just a collection of parts but a reflection of Faxon’s dedication to precision, innovation, and aesthetics. Draped in a custom Cerakote finish, this builder set stands out, making a statement both in function and design.
At the heart of this exceptional set is the Upper receiver, which undergoes a rigorous truing process at Faxon’s factory. This exacting process ensures a perfectly aligned and balanced receiver, laying the foundation for an optimally performing firearm. The internal bore is carefully honed, providing a smoother pathway for the bolt carrier group. This meticulous attention to detail not only enhances the action but also prolongs the life of the bolt carrier group.
But it’s not just about performance. Faxon knows the importance of aesthetics combined with function. The shell deflector has been ingeniously hollowed out. This design innovation serves a dual purpose: it shaves off excess weight, optimizing the balance of the firearm, and it adds a visually striking element that elevates the overall look of the AR-15.
To further the detail-oriented design, manually engraved T-marks adorn the upper. These aren’t just regular engravings; they are crafted to withstand the test of time. Even after applying any coating, these marks remain visible, ensuring you never lose those essential reference points.
The quality of the material used in the set is second to none. Crafted from 7075-T6 Forged Aluminum, you get a balance of lightweight agility and robust strength. A dual finish is applied to the material. First, it receives a Type III Hard Coat Anodizing, which adds to its resistance against wear and tear. This is then complemented by the custom Cerakote finish, amplifying its aesthetic appeal and adding an additional layer of protection.
One of the standout features of this builder set is its versatility. It is compatible with all intermediate cartridges. However, it’s worth noting that larger bore rounds, such as .458, might not function optimally in the intermediate upper, ensuring users have clarity on the set’s capabilities.
To complete the ensemble, the set includes the Faxon G2 Streamline Aluminum M-LOK Handguard. This component is a testament to Faxon’s dedication to ergonomic design, functionality, and style, ensuring that users have a comfortable and efficient grip while maintaining the sleek look of their firearm.
The Limited Edition Faxon AR-15 Builder Set is more than just parts for your firearm; it’s a fusion of precision engineering, innovative design, and unmatched quality. Whether you’re a seasoned shooter or a firearm hobbyist, this set promises to elevate your AR-15 experience.
Limited Edition Faxon 13″ AR-15 Builder Set – Combat Grey
The Limited Edition Faxon AR-15 Builder Set is not just an assembly of parts; it’s a testament to impeccable craftsmanship, innovative design, and a dedication to precision. Draped in a custom Cerakote finish, this builder set not only offers unparalleled function but also stands out with its unique aesthetics.
At the forefront of this masterpiece is the Upper receiver, which is meticulously trued by the expert team at Faxon’s own factory. This ensures an unparalleled level of precision, leading to enhanced firearm performance. The internal bore, as a part of this process, undergoes careful honing. This smoothing out not only optimizes the action of the bolt carrier group but also promises an extended life for the assembly, reducing wear over time.
A balance of aesthetics and function is evident in the intricately hollowed-out shell deflector. This design choice does more than just enhance the visual appeal. By reducing material, it achieves a significant weight reduction, ensuring the firearm remains balanced and agile in the user’s hands.
Attention to detail is a hallmark of Faxon, showcased by the manually engraved T-marks on the upper. These are not just ornamental; they serve a functional purpose. Designed to endure, they remain prominently visible, even after applying coatings. This ensures users can rely on them for reference over extended periods of use.
Precision continues with a tighter tolerance on the lugs, ensuring a snug and superior fit. It’s these minute details that distinguish a good firearm from a great one. The choice of material is critical in achieving a balance of durability and agility. Crafted from the robust 7075-T6 Forged Aluminum, this set promises resilience without adding unnecessary weight.
The exquisite finish of the set deserves a mention. The base layer is a Type III Hard Coat Anodizing, known for its resistance against wear, corrosion, and abrasion. Over this, the custom Cerakote is applied, enhancing its visual appeal and adding another protective layer against external elements.
While the set is meticulously designed, it is also versatile in its function. It’s compatible with all intermediate cartridges, though it’s worth noting for enthusiasts that larger bore rounds like .458 might not optimally function in this intermediate upper.
Rounding off this exceptional set is the Faxon G2 Streamline Aluminum M-LOK Handguard. This inclusion ensures users experience comfort, efficiency, and style, all while maintaining a cohesive look for their firearm.
In essence, the Limited Edition Faxon AR-15 Builder Set is a fusion of art and engineering. For the discerning shooter or the firearm connoisseur, this set is more than an upgrade; it’s an experience in precision and design.
*Also available in Charcoal Green
Wrapping it Up!
The best choice of lower receiver ultimately boils down to your goals, budget, and familiarity with AR mechanics.
For those comfortable with the mechanics of the AR platform, a stripped lower receiver offers a more customized hands-on experience.
Conversely, if you don’t have the mechanical aptitude to install all the parts of the lower receiver or just simply don’t have the time, a complete lower receiver is your ticket, often just requiring you to attach it to the upper.
Remember to prioritize quality. While fancy features can be enticing, the foundation of a durable and reliable AR build is a high-quality lower.
And speaking of quality, we hold Faxon Firearms in the highest regard as our preferred choice for lower receivers. If you have questions, drop us a comment below.