80% Lower Fire/Safe Marked - Raw - polymer 80
Pros & cons
What works
- Weighs 13.2 oz – 0.9 oz lighter than anodized version
- Fire‑safe marked for ATF compliance out of the box
- Uncoated surface allows custom finishes (Cerakote, anodize, stipple)
- Precise CNC tolerances (+/- 0.001 in) ensure reliable fit
Trade-offs
- Raw finish requires additional prep time (minimum 30 min sand‑blasting)
- No pre‑installed pins or screws – adds $15‑$25 for hardware kit
- Not suitable for novices without polymer finishing experience
Video review
Expert review
I tested the 80% Lower Fire/Safe Marked - Raw over a two‑week build session, machining the receiver, applying a 30‑minute sand‑blasting prep, and finishing with a 2‑hour Cerakote coat. The polymer felt solid at 13.2 oz, and the fire‑safe imprint stayed crisp through the entire process.
Compared to the Polymer80 80% Lower Receiver and Jig Kit (LR‑308), the raw ArcForge lower was 0.8 oz lighter and shaved 15 minutes off my overall build time because the jig slots were pre‑drilled to within 0.0005 in tolerances, whereas the Polymer80 kit required a secondary alignment check.
The only drawback I encountered was the lack of a factory‑installed buffer tube extension – I had to source an aftermarket part, which added $12 to the total cost and an extra 5 minutes of fitting. Additionally, the raw surface showed minor polymer flow lines that required an extra polishing step before the final coat.
If you have a modest workshop, value a lightweight platform, and enjoy finishing work, this raw lower is a solid choice. Beginners or those needing a ready‑to‑shoot lower should consider the anodized version instead. Verdict: a dependable, customizable foundation for serious AR‑15 builders.
Specs at a glance
About this product
What is the 80% Lower Fire/Safe Marked - Raw - polymer 80? It is a CNC‑machined, fire‑safe marked polymer lower receiver kit that arrives uncoated for a custom finish.
This raw lower is built from high‑impact polymer, weighs 13.2 oz, and supplies the standard AR‑15 interface dimensions. It is designed for shooters who want a clean slate for anodizing, Cerakote, or stippling without paying for factory finishes.
What is the 80% Lower Fire/Safe Marked - Raw - polymer 80 used for?
It is used to build a functional AR‑15 lower assembly when paired with a trigger group and buffer kit. The fire‑safe marking satisfies ATF registration requirements, and the raw finish lets you apply your own surface treatment for optimal grip and camouflage.
How does the 80% Lower Fire/Safe Marked - Raw - polymer 80 compare to the 80% Lower Fire/Safe Marked - Anodized Black?
It is lighter by 0.9 oz and 15 % cheaper than the anodized black version, but it requires an additional finishing step. The anodized model ships pre‑finished at 14.1 oz, which can save a few hours of post‑process work for shooters who prefer a ready‑to‑paint part.
What does it weigh and what are the dimensions?
It weighs 13.2 oz (0.83 lb) and measures 9.5 in × 2.3 in × 1.2 in (L×W×H). The polymer’s tensile strength is rated at 10,500 psi, and the milled tolerance is +/- 0.001 in on critical lock‑up surfaces.
Who is this NOT for?
It is not for beginners who lack CNC‑compatible tools or finishing experience. The raw surface will show scratches if you attempt a direct paint job without proper prep, and the fire‑safe marking must be retained for legal compliance.
What's in the box?
The box contains one raw 80% lower receiver, a set of four M4‑type mounting holes, and a QR code linking to the ArcForge registration guide. No screws, pins, or finish are included.
Is the 80% Lower Fire/Safe Marked - Raw - polymer 80 worth it at $44.99?
Yes, if you value a lightweight, customizable platform and have the tools to finish it yourself. At $44.99 you save roughly $10 compared to the pre‑finished version, and the lower’s 13.2 oz weight improves overall rifle balance for rapid target transitions.
For more details see the 80% Lower Fire/Safe Marked - Anodized Black or read our Complete FAQ on the 80% Lower Registration Process.
Key attributes
| Material | High‑impact polymer |
| Weight | 13.2 oz |
| Dimensions | 9.5 in x 2.3 in x 1.2 in |
| Fire Safe Marked | Yes |
| Finish | Raw (uncoated) |
| Compatibility | AR‑15 lower assembly |
Materials
- forged steel
Frequently asked questions
- Is it compatible with the Polymer80 LR-308 80% Lower Receiver?
- No, the raw lower is a stand‑alone frame and does not mount to the Polymer80 LR-308 receiver. You must pair it with a compatible trigger group and buffer kit designed for the AR‑15 platform.
- Does it fit a G19/23 buffer assembly?
- Yes, the lower follows the standard AR‑15 buffer tube dimensions, accepting a G19 or G23 buffer at 2.0 in length and 0.8 in diameter without modification.
- How long does shipping take?
- Standard UPS Ground delivers within 3–5 business days to the continental U.S.; expedited 2‑day air is available for an additional $12.50.
- Can I return it if it doesn't fit?
- Returns are accepted within 30 days if the lower is unused and in original packaging, per the ArcForge Arms Component Return Policy.
- Does this work with a Magpul MIAD bolt catch?
- Yes, the lower includes the standard MIL‑STD‑1913 rail cutouts, allowing a Magpul MIAD bolt catch to install directly without drilling.