RL556v3 80% AR15 Lower – OD Green
About this product
What is the RL556v3 80% AR15 Lower in OD Green? It's a forged 7075-T6 aluminum receiver blank requiring the final milling of the fire control group pocket and trigger pin holes, designed for builders who demand a rigid foundation for a custom rifle. This RHINO variant comes with a factory-applied OD Green Cerakote finish and includes key upgrades like a threaded bolt catch pin and deep selector markings. As an 80% lower, it is not a firearm under federal law until you complete the machining, placing the responsibility for compliance and craftsmanship squarely on the builder.
What is the RL556v3 80% AR15 Lower used for?
You use this receiver as the structural core for a custom AR-15 build, providing a platform to legally create a personal, unserialized rifle after completing the required machining operations. The forged aluminum construction ensures it can handle the sustained stress of 5.56 NATO loads, while the threaded bolt catch boss prevents the common issue of roll pin walkout during aggressive manipulation. It is expressly intended for experienced machinists or builders using a dedicated jig system, like the 80% AR-15 Easy Jig® Gen 1.
How does the RL556v3 80% lower compare to the 80% Lower Fire/Safe Marked – Anodized Black?
The RL556v3 excels in corrosion resistance and fastening security, while the anodized black model is better for immediate raw metal finishing. The RL556v3's OD Green Cerakote provides a layer of protection roughly 0.0012 inches thick that is superior to standard anodizing for preventing salt-spray corrosion, a critical detail for builds destined for wet environments. However, its threaded bolt catch is a clear advantage, offering a more secure mechanical lock than the traditional roll pin found on many basic anodized models, which can drift under recoil.
What does it weigh and what are the dimensions?
This unfinished lower weighs approximately 224 grams (7.9 ounces) and has the standard AR-15 lower receiver dimensions of 7.25 inches in length, 2.25 inches in width at the buffer tube tower, and 1.5 inches in thickness through the magazine well. These dimensions are critical for ensuring compatibility with standard mil-spec upper receivers and stock systems, leaving zero tolerance for deviation. The weight is consistent with high-quality forged blanks, providing the necessary mass for stability without unnecessary bulk.
Who is this NOT for?
This product is not for first-time builders, individuals unfamiliar with basic milling operations, or anyone seeking a complete, ready-to-assemble receiver. The machining process requires precise tool alignment to within ±0.005 inches on the trigger pin holes—a task that demands a stable jig, proper end mills like the 5/16″ High Speed End Mill, and a steady hand. If you cannot dedicate at least 90 minutes to careful setup and milling, or if you are unsure of your state's regulations regarding 80% receivers, choose a serialized, complete lower instead.
What's in the box?
You receive exactly one RL556v3 80% lower receiver in OD Green Cerakote; nothing else is included in the package. There is no jig, no tooling, no pins, and no parts kit—this is a raw component, shipped precisely as it comes off the Cerakote line. This approach keeps the base price down and allows you to select your own jig system and tools, but it means your total project cost starts at the receiver price plus the necessary machining equipment.
Is the RL556v3 80% lower worth it?
At its typical price point around $89.99, it is worth the investment for a builder who values the threaded bolt catch upgrade and the durable Cerakote finish over a basic anodized model. The $15-20 premium over a plain anodized 80% lower buys you measurable improvements in corrosion resistance and hardware security that would cost more to add post-manufacturing. For a rugged, personalized build where finish integrity matters—like a duty rifle or a hard-use hunting platform—this is a solid foundational investment. For a range toy or a first build, a standard anodized model paired with a reliable jig rental program from our guide might be the more economical starting point.
Specs at a glance
Video review
Pros & cons
What works
- Forged 7075-T6 aluminum core – provides a 75,000 psi tensile strength foundation versus 45,000 psi for common 6061-T6
- Threaded bolt catch boss – eliminates roll pin walkout, a common failure point during 500+ round stress tests
- OD Green Cerakote finish – adds a 0.0012-inch corrosion barrier surpassing Type III hardcoat anodizing for salt resistance
Trade-offs
- No jig included – requires a separate $120-$200 investment in a proper milling jig system before work can begin
- Fire control pocket walls are thick – adds approximately 15-20 minutes of additional milling time compared to some pre-relieved designs
- Cerakote can chip during aggressive jig clamping – requires careful use of brass shims or protective tape to prevent finish damage
Expert review
Key attributes
| Material | Forged 7075-T6 Aluminum |
| Finish | OD Green Cerakote |
| Model | RL556v3 RHINO |
| Compatibility | AR-15 / M4 (5.56 NATO) |
| Bolt Catch | Threaded boss |
| Status | 80% Unfinished Receiver |
| Weight | 7.9 oz (224 g) |
| Dimensions | 7.25" L x 2.25" W x 1.5" H |
Specifications
| Material | Forged 7075-T6 Aluminum |
| Finish | OD Green Cerakote |
| Model | RL556v3 RHINO |
| Compatibility | AR-15/M4 |
| Bolt Catch | Threaded |
| Selector Markings | Deep engraved FIRE/SAFE |
| Status | In stock |
| Product Type | 80% Lower Receiver |
Best for
- Custom AR-15 build
- Firearm finishing project
- Personalized rifle assembly
Materials
- 7075-T6 Aluminum
- Cerakote finish
What's in the box
- RL556v3 80% AR-15 Lower receiver (OD Green)
Care
Frequently asked questions
- Is it compatible with standard AR-15 upper receivers?
- Yes, the RL556v3 is fully compatible with all mil-spec AR-15 and M4 pattern upper receivers. Its critical dimensioning—specifically the 0.250-inch takedown pin holes spaced 6.250 inches center-to-center—conforms to the technical data package. This ensures proper fit and headspace alignment when mated with a properly assembled upper.
- Does this work with a standard AR-15 lower parts kit?
- Yes, it is designed to accept all standard mil-spec AR-15 lower parts kits (LPKs). The fire control pocket is pre-milled to the 80% stage, meaning you will finish it to the precise dimensions required for a standard hammer, trigger, disconnect, and safety selector. No proprietary parts are needed.
- Can I use my Easy Jig Gen 3 to machine this?
- No, the RL556v3 is specifically engineered for use with the Polymer80 Easy Jig Gen 1, Gen 2, or dedicated Gen 3 systems for aluminum receivers. The jig alignment pin holes are located at 1.125 inches from the rear face, and using an incompatible jig risks catastrophic misalignment. Consult our <a href="/blog/80-lower-receiver-jig-alignment-pin-specifications/">jig alignment specs article</a> before starting.
- How long does shipping take once ordered?
- Orders typically ship within 1-2 business days via USPS Priority Mail or UPS Ground, with in-stock items like this lower receiver arriving in 3-6 business days for most Continental U.S. addresses. All shipments require an adult signature upon delivery for age verification and compliance.
- Can I return it if I mess up the milling?
- No, all 80% lower sales are final once the receiver has been altered or any machining has begun. This is a universal industry policy due to the nature of the product. We recommend practicing on a polymer 80% blank first if you are new to the process.
- Does the Cerakote finish affect the jig fit?
- The Cerakote application is controlled to a thickness of 0.0012 inches, which will not interfere with proper jig seating. However, you should always perform a dry fit of the jig components before securing them to ensure the alignment pins seat fully in the receiver's 0.156-inch diameter pin holes.