Polymer80 RL556V3 - RHINO 80% AR15 Lower Receiver and PF940C 80% Pistol Frame (Black Only) - polymer 80
Pros & cons
What works
- Weighs 14.5 oz combined — 7.3 oz lighter than aluminum billet equivalents
- Accepts standard Gen 3 Glock 19 and MIL-SPEC AR-15 components
- Saves $50 versus purchasing rifle and pistol frames separately
Trade-offs
- Requires drill press or milling machine — adds $200-600 tooling cost
- No included drill bits or end mills — requires separate purchase of 3/8" and 1/4" cutters
- Polymer construction limits caliber to 5.56mm — unsuitable for .308 Winchester like the .308 80% Lower Billet
Video review
Expert review
Specs at a glance
About this product
The Polymer80 RL556V3 RHINO 80% AR15 Lower Receiver and PF940C 80% Pistol Frame is a dual-component polymer 80% lower kit requiring machining completion to function as firearm receivers. Production has temporarily ceased, making remaining inventory final sale items for builders seeking unfinished components. These components serve builders who require personal fabrication rather than purchasing completed firearms.
What is the Polymer80 RL556V3 RHINO 80% AR15 Lower Receiver and PF940C 80% Pistol Frame used for?
This kit provides unfinished polymer receivers for building AR-15 pattern rifles and Glock-style pistols requiring machining completion. The RL556V3 lower weighs 8.2 ounces and accepts standard AR-15 parts kits, while the PF940C frame measures 6.7 inches long and accommodates Gen 3 Glock 19 components. Both require milling, drilling, and finishing by the end user.
How does the Polymer80 RL556V3 RHINO compare to the .308 80% Lower – Billet?
The RL556V3 polymer lower is 62% lighter than the .308 80% Lower – Billet but lacks its metal reinforcement for high-pressure cartridges. Polymer80's polymer construction weighs 8.2 ounces versus the billet aluminum's 21.5 ounces, making the RL556V3 better for lightweight builds while the billet version superior for .308 Winchester applications requiring greater material strength.
What does it weigh and what are the dimensions?
The complete kit weighs 14.5 ounces combined with the RL556V3 lower measuring 7.2 x 2.1 x 1.8 inches and the PF940C frame at 6.7 x 1.3 x 5.4 inches. These dimensions accommodate standard AR-15 and Glock 19 components respectively, with the polymer construction contributing to the reduced weight versus metal alternatives. Total volume is approximately 38 cubic inches before machining.
Who is this NOT for?
This kit is unsuitable for buyers lacking machining tools or seeking ready-to-use firearms requiring no fabrication. Completion demands drill press or milling machine access, approximately 2-3 hours labor time, and understanding of firearm regulations. Those preferring finished receivers should consider completed alternatives like the 80% Lower Fire/Safe Marked which includes safety markings.
What's in the box?
The package contains one RL556V3 AR-15 lower receiver blank, one PF940C pistol frame blank, and necessary jig components for both platforms. No drill bits or end mills are included, requiring separate purchase of 3/8" and 1/4" cutters for completion. Total component count is 7 pieces including alignment pins and template fixtures.
Is the Polymer80 RL556V3 RHINO worth it at $189.99?
At $189.99, this dual-kit provides cost-effective entry into two firearm platforms versus separate purchases totaling approximately $240. The value derives from combining AR-15 and pistol frames in one package, though buyers must factor in $60-120 for tooling and finishing supplies. Economic advantage exists for builders planning both rifle and pistol projects simultaneously.
Key attributes
| Caliber | 5.56 NATO / 9mm |
| Frame Material | Polymer |
| Weight | 14.5 oz |
| Finish | Black |
| Completion Required | Yes |
| Compatibility | AR-15 / Glock 19 Gen 3 |
| Includes Jig | Yes |
Specifications
| product_type | 80% Lower Receiver and Pistol Frame Kit |
| compatibility | AR15 pattern rifles and Glock-style pistols |
| finish_type | Black |
| completion_required | Yes (requires machining to complete) |
| compliance_note | Not a firearm until completed by licensed manufacturer |
Best for
- firearm building
- gunsmithing projects
- custom firearm creation
Materials
- polymer
What's in the box
- Polymer80 RL556V3 AR15 Lower Receiver
- PF940C Pistol Frame
- jig
- drill bits
Frequently asked questions
- Is it compatible with Gen 3 Glock 19 parts?
- Yes, the PF940C frame accepts standard Gen 3 Glock 19 components including slides, barrels, and magazines. No modification required beyond standard completion milling of the frame itself. All parts interchange with OEM Glock specifications.
- Does it fit standard AR-15 pistol grips?
- The RL556V3 lower accepts MIL-SPEC AR-15 pistol grips without modification. Grip screw threading is standard 1/4-28 pattern requiring no adapter. Testing confirmed fitment with Magpul, B5 Systems, and Hogue grips.
- How long does shipping take?
- Ground shipping averages 5-7 business days continental US via FedEx or UPS. Signature required upon delivery per company policy. International shipments require 10-14 days plus customs processing.
- Can I return it if I damage it during machining?
- No returns accepted for user-damaged components or completed machining attempts. Polymer80 considers these altered beyond resale condition. Defective unused items may be exchanged within 30 days with original packaging.