Polymer80 P80-JIG-RL556v3 Jig Kit - polymer 80
Video review
Expert review
About this product
What is the Polymer80 P80-JIG-RL556v3 Jig Kit? It is a precision‑engineered jig set for assembling a 5.56×45mm AR‑15 lower receiver from Polymer80's RL556v3 80% lower.
This kit streamlines the milling process, reduces material waste, and ensures repeatable tolerances for competitive shooters and DIY builders alike.
What is the Polymer80 P80-JIG-RL556v3 used for?
It is used to mill the critical dimensions of a RL556v3 lower receiver so it fits standard AR‑15 parts.
The jig clamps to the lower blank, guides the drill and milling bits, and guarantees the trigger, safety, and buffer tube holes are within 0.01" of spec, saving you up to 2 hours of trial‑and‑error work.
How does the Polymer80 P80-JIG-RL556v3 compare to the Vortex Optics AR‑15 Lower Jig?
It offers tighter tolerances than the Vortex Optics AR‑15 Lower Jig, with a stated drill‑guide deviation of ±0.005" versus ±0.012" for the Vortex.
The reinforced steel body of the Polymer80 jig also weighs 21 oz, 5 oz lighter than the Vortex model, making it easier to handle during setup.
What does it weigh and what are the dimensions?
The jig kit weighs 21 oz (595 g) and measures 7.5" × 4.2" × 1.8" (190 mm × 107 mm × 46 mm).
Its compact footprint fits in a standard tool bag and the included handle is 4.0" long for precise positioning.
Who is this NOT for?
It is not for shooters who prefer fully finished, ready‑to‑use lowers or lack basic machining tools.
If you cannot operate a drill press or a CNC mill, the jig’s benefits are inaccessible and you may waste time and material.
What's in the box?
The box contains one steel jig base, four interchangeable drill guides, two hole‑blocking pins, a 1/4" hex key, and a PDF of step‑by‑step milling instructions.
All components are labeled for quick assembly, and the PDF includes a 12‑minute video tutorial.
Is the Polymer80 P80-JIG-RL556v3 worth it at $50.99?
Yes, at $50.99 it delivers professional‑grade accuracy for a fraction of the cost of a CNC service.
Considering a typical CNC mill charges $150‑$200 per lower, the jig saves you at least $100 while delivering tolerances within 0.01".
For more builds see our see Polymer80 80% Lower Receiver and Jig Kit (LR-308) or read the ArcForge Arms Bulk Order Lead Times: What Shooters Need to Know.
Specs at a glance
Pros & cons
What works
- Weighs 21 oz — 5 oz lighter than competing jigs
- Tolerances ±0.005" guarantee parts fit without filing
- Compact 7.5"×4.2"×1.8" size fits in a tool bag
- Includes video tutorial – reduces setup time by ~30 min
Trade-offs
- Requires a drill press or CNC mill – not a plug‑and‑play solution
- No pre‑installed stippling – adds $40‑$80 finishing cost if desired
- Limited to RL556v3 lower; not universal for all 80% lowers
Key attributes
| Caliber | 5.56 NATO |
| Lower Model | RL556v3 |
| Weight | 21 oz (595 g) |
| Dimensions | 7.5" x 4.2" x 1.8" (190 mm x 107 mm x 46 mm) |
| Material | Heat‑treated steel |
| Condition | New |
Frequently asked questions
- Is it compatible with the RL556v3 lower blank?
- Yes, the jig is machined specifically for the RL556v3 80% lower. It fits the blank's 1.75" width and aligns with the milled buffer tube pocket.
- Does it fit a standard AR‑15 trigger group?
- It does. The guide holes are sized for a 0.629" trigger pin and a 0.378" safety selector, matching standard AR‑15 components.
- How long does shipping take?
- Standard US shipping averages 3‑5 business days, with a flat rate of $7.99. Expedited options deliver within 2 days for an additional $15.
- Can I return it if it doesn't fit?
- Returns are accepted within 30 days if the jig is unused and in original packaging. A restocking fee of 10 % applies.
- Does this work with a standard 1/4‑20 drill press?
- Absolutely. The jig’s base includes a 1/4‑20 threaded mount that aligns with most bench‑top drill presses.