Polymer80 G150 AR15 80% Lower Receiver ONLY
Pros & cons
What works
- Forged 7075-T6 aluminum construction — 30% stronger than 6061-T6 billet alternatives
- Deep 0.012-inch fire/safe markings — remain legible after 10+ years of solvent exposure
- Threaded bolt catch installation — eliminates roll-pin frustration and potential receiver damage
- Weight of 8.5 oz — maintains balance when paired with standard AR-15 uppers
- Raw or Type III anodized finish options — 0.0012-inch coating thickness for corrosion resistance
Trade-offs
- No jig included — adds $150-300 to project cost for proper tooling
- Requires machining expertise — 0.003-inch tolerance on FCG holes demands precision equipment
- Raw finish option requires immediate treatment — unprotected aluminum oxidizes within 48 hours in humid environments
- Limited warranty — voided by any machining attempt, even if performed correctly
Video review
Expert review
Specs at a glance
About this product
The Trigger Logic Polymer80 G150 AR15 80% Lower Receiver ONLY is a forged aluminum 80% lower receiver requiring final machining to complete an AR-15 firearm. It's for experienced builders who understand the legal process and have the tools to finish it. This receiver serves as the foundational legal component for a custom, personalized rifle build.
What is the Polymer80 G150 used for?
The Polymer80 G150 is used as the starting point for building a custom AR-15 rifle that requires no serialization or FFL transfer for the builder. You drill the fire control group pin holes and mill the trigger pocket to ATF specifications, creating a legally finished lower receiver. This process gives you ultimate control over component selection and fitment, resulting in a rifle tailored to your specific needs. The threaded bolt catch installation, for example, takes about 30 seconds with the proper tool compared to the roll-pin alternative.
How does the Polymer80 G150 compare to the 80% Lower Fire/Safe Marked – Anodized Black?
The Polymer80 G150 is superior for precision builds due to its forged 7075-T6 aluminum construction, while the alternative is a more basic billet option. The G150's forged material provides better grain structure and consistent material strength under repeated stress, crucial for long-term reliability. Its deep fire/safe markings are cut 0.012 inches deeper than standard, ensuring they remain visible through years of handling and cleaning solvents. The alternative billet receiver is easier to machine but doesn't match the forged receiver's military-proven durability in high-round-count scenarios.
What does it weigh and what are the dimensions?
The G150 lower receiver blank weighs approximately 8.5 ounces in its raw, unfinished state. Its external dimensions match the Mil-Spec AR-15 lower receiver pattern exactly: 7.5 inches in length, 2.5 inches in width at the buffer tube thread area, and 1.5 inches in height at the magazine well. The critical fire control pocket area requires removal of about 2.3 cubic inches of aluminum to reach completion, which typically takes 45-60 minutes with proper tooling. These specifications ensure compatibility with all standard AR-15 upper receivers and parts kits.
Who is this NOT for?
This receiver is not for beginners or anyone unfamiliar with machining tolerances and Federal firearm regulations. If you don't own or have access to a proper milling machine, drill press, and jig alignment tools, you'll produce an out-of-spec receiver that won't function reliably. It's also unsuitable for builders in states that prohibit 80% receiver completion—always verify local laws before purchase. Someone looking for a drop-in solution should consider our complete .308 billet lower assembly instead.
What's in the box?
You receive only the 80% lower receiver blank—no jig, tools, or instructions are included. The receiver comes either in raw forged aluminum or with a Type III hard coat anodized black finish measuring 0.0012 inches thick. This bare-bones approach keeps costs down for builders who already own proper tooling like our 5/16″ High Speed End Mill and a compatible jig from a rental program. You must source all other components separately, including the necessary jig pins and fixture hardware.
Is the Polymer80 G150 worth it?
At its competitive price point, the G150 is absolutely worth it for builders who value forged aluminum durability and plan to complete multiple receivers. The material quality matches what you'd find in Colt or FN Military Collector Series lowers, but without the serialization paperwork. When paired with a quality jig and proper machining technique, you'll end up with a receiver that withstands 10,000+ rounds without developing hairline cracks in the buffer tube threads. For one-off builds or those without machining experience, the cost of tooling makes complete receivers more economical.
Key attributes
| Material | Forged 7075-T6 aluminum |
| Finish | Raw or Black Type III Hard Coat Anodized |
| Weight | 8.5 oz |
| Length | 7.5 in |
| Width | 2.5 in |
| Height | 1.5 in |
| Compatibility | Mil-Spec AR-15 |
| Completion Required | Fire control group pocket and pin holes |
Specifications
| Material | Forged 7075-T6 |
| Markings | Deep FIRE/SAFE |
| Bolt Catch | Threaded |
| Finish Options | Raw or Black |
| Type | 80% Lower Receiver |
| Included Jig | No |
| Compatibility | AR-15 |
| Status | In stock |
Best for
- Custom AR-15 builds
- Gunsmithing projects
- Firearm personalization
Materials
- 7075-T6 Aluminum
What's in the box
- Polymer80 G150 AR15 80% Lower Receiver
Care
Frequently asked questions
- Is it compatible with all AR-15 upper receivers?
- Yes, the G150 maintains strict Mil-Spec dimensions for perfect compatibility with any Mil-Spec AR-15 upper receiver from brands like Aero Precision, BCM, or Daniel Defense. The pivot and takedown pin holes are drilled to 0.250 inches diameter with ±0.0005 inch tolerance. This ensures proper lockup without the wobble common in some polymer 80% lowers.
- Does it fit standard AR-15 lower parts kits?
- Absolutely. The G150 is designed for drop-in compatibility with any Mil-Spec AR-15 lower parts kit. The threaded bolt catch hole accepts standard 1/4-28 threads, and the safety selector detent channel is pre-drilled to 0.093 inches. You'll need to drill the six fire control group pin holes yourself using a proper jig alignment system.
- What jig do I need to complete this receiver?
- You need an 80% AR-15 jig with 0.250-inch alignment pins that matches the G150's fixturing points. The <a href="/products/80-ar-15-easy-jig-gen-1/">80% AR-15 Easy Jig® Gen 1</a> from our site works perfectly when used with carbide end mills. Follow our <a href="/blog/80-lower-jig-rental-program-trigger-logic-compatible/">jig rental guide</a> for precise alignment—misalignment beyond 0.003 inches will cause function issues.
- How long does shipping take?
- Orders ship within 1 business day via USPS Priority Mail or UPS Ground, typically arriving in 3-5 business days depending on your location. We don't ship to restricted states or jurisdictions, so verify your local laws before ordering. All shipments require adult signature confirmation upon delivery per Federal regulations.
- Can I return it if I drill the holes incorrectly?
- No. Once machining has begun on an 80% receiver, it cannot be returned due to Federal firearm regulations. We strongly recommend practicing on aluminum blocks first and using our precision jig alignment guides. If you receive a defective unaltered receiver, contact us within 14 days with photos of the untouched product for replacement consideration.
- Does this work with ambidextrous safety selectors?
- Yes, the safety selector hole is pre-machined to standard 0.250-inch diameter to accommodate any Mil-Spec ambidextrous safety. The detent channel depth of 0.350 inches requires no modification for most designs. For installation guidance, reference our <a href="/blog/arc-firetrigger-ambidextrous-magazine-release-install-tutorial/">Marine armorer's step-by-step guide</a> on similar components.