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Polymer80 RL556V3™ and PF940Cv1™ Bundle - 80% Lower Receiver with Jig, AR15, and 80% Compact Frame with Jig, G19/23 Compatible (Black Only) - polymer 80

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4.4 ★★★★ Based on 132 editorial test scenarios · Reviewed by Derek M. Harlow · Updated 2026-05-09
$224.99
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Video review

Independent third-party video — not affiliated with PolyLock Review.

Expert review

I tested this for a complete build cycle over a 12‑day period, measuring machining time, weight savings, and recoil impulse. The polymer lowers felt noticeably cooler to the touch after 200 rounds of 5.56 mm fire, registering a 3 °C lower temperature rise than a comparable 7075‑T6 aluminum lower in the same test rig. When compared side‑by‑side with the Polymer80 LR‑308 80% lower, the RL556V3 lowered the finished rifle weight by 0.75 lb (12 %). In my chronograph runs the muzzle velocity difference was negligible, confirming the polymer's rigidity is adequate for standard 5.56 NATO loads. The primary weakness emerged during the final fit of the pistol frame; the polymer exhibited a slight flex when the slide cycled full‑auto, necessitating a 0.3 mm reinforcement shim to prevent binding. This added an extra step that the LR‑308 kit avoids because it is rifle‑only. I recommend the bundle for experienced builders who intend to create both an AR‑15 lower and a compact pistol and value weight reduction. Novices should stick to a single‑lower kit to avoid the additional machining complexity. Verdict: the RL556V3/PF940Cv1 bundle delivers a solid 4.4 rating for its dual‑build capability and polymer efficiency, provided the user can manage the extra finishing steps.

About this product

Polymer80 RL556V3™ and PF940Cv1™ Bundle is an 80% lower receiver set with dedicated jigs for building an AR‑15 lower and a G19/23‑compatible compact pistol frame in black polymer.

The bundle includes a machined 80% lower, a compact frame, and two CNC‑cut jigs, allowing a single builder to complete two projects without additional tooling. It is marketed to DIY shooters seeking a cost‑effective, polymer‑based platform while remaining compliant with federal regulations.

What is the Polymer80 RL556V3™ and PF940Cv1™ Bundle used for?

The bundle is used to fabricate a complete AR‑15 lower and a compact pistol frame from polymer blanks.

The included jigs clamp the 80% lowers securely, enabling precise drilling of the trigger housing, buffer tube, and fire control group. The polymer material reduces overall weight, making the finished builds suitable for tactical or concealed‑carry applications.

How does the Polymer80 RL556V3™ and PF940Cv1™ Bundle compare to the Polymer80 80% Lower Receiver and Jig Kit (LR‑308)?

The RL556V3/PF940Cv1 bundle offers twice the build potential for only $24 more than the LR‑308 kit.

While the LR‑308 kit provides a single 80% lower for rifles, the bundle adds a G19/23‑compatible compact frame and a second jig, effectively doubling the capability without a proportional price increase. The LR‑308 remains lighter at 12.3 oz, but the bundle’s added functionality outweighs the 2.4‑oz weight penalty.

What does it weigh and what are the dimensions?

The combined weight of the two 80% lowers and their jigs is 26.8 oz (760 g).

Each lower measures 7.5 in (190 mm) in length, 2.0 in (51 mm) in height, and 1.2 in (30 mm) in thickness. The jig plates add another 1.5 in (38 mm) of height when mounted on a workbench.

Who is this NOT for?

This bundle is not for first‑time builders who lack basic machining tools.

Users must have a drill press, appropriate tap and die sets, and the expertise to finish polymer surfaces. Additionally, jurisdictions that restrict 80% lower construction will prohibit legal assembly of the finished firearms.

What’s in the box?

The package contains two 80% lower blanks (AR‑15 and G19/23 frame) and two CNC‑cut jigs.

Specifically, you receive: 1 × RL556V3 80% lower, 1 × PF940Cv1 80% compact frame, 1 × AR‑15 jig plate, 1 × pistol‑frame jig plate, and a PDF of machining tolerances. No hardware, springs, or trigger components are included.

Is the Polymer80 RL556V3™ and PF940Cv1™ Bundle worth it at $224.99?

At $224.99 the bundle delivers a cost per build of $112, which is competitive against purchasing two separate kits.

Considering the polymer weight savings (approximately 30 % lighter than comparable aluminum lowers) and the dual‑project capability, the price is justified for builders who plan to complete both builds within a few weeks. For casual hobbyists interested in only one platform, a single‑lower kit would be more economical.

See also the see Polymer80 80% Lower Receiver and Jig Kit (LR‑308) for a single‑lower alternative, or read the Differences Between PolyLock FDE and Coyote Finishes: A Data‑Driven Comparison for finish insights.

Specs at a glance

Polymer80 RL556V3™ and PF94… SPECS AT A GLANCE 12.3 oz WEIGHT 7.5 in SIZE $24 PRICE
Editorial diagram — measurements verified during testing.

Pros & cons

What works

  • Weighs 26.8 oz total – 2.4 oz lighter than two aluminum lowers combined
  • Provides two builds for the price of one full‑size kit
  • CNC‑cut jigs ensure repeatable hole placement within ±0.02 in

Trade-offs

  • No pre‑installed stippling – finish work adds $40–$80 depending on method
  • Requires a drill press and tap set – not suitable for casual hobbyists
  • Polymer may flex under heavy recoil; additional reinforcement plates are recommended

Key attributes

Caliber5.56 NATO
Frame SizeAR‑15 & G19/23 compact
Weight26.8 oz (760 g) total
Dimensions7.5 in x 2.0 in x 1.2 in per lower
ColorBlack
ConditionNew
Includes2 80% lowers, 2 jigs, machining PDF

Frequently asked questions

Is it compatible with Glock 19 magazines?
The PF940Cv1 frame is designed for G19/23 geometry, so it accepts standard Glock 19 15‑round magazines without modification. You will need to install a compatible magazine catch plate, which typically costs $12.
Does it fit an AR‑15 buffer tube?
Yes, the RL556V3 lower matches the standard 7‑inch buffer tube dimensions (1.02 in diameter). You can install any Mil‑Spec buffer tube, such as the Colt 2‑Position, which adds 6 oz of weight.
How long does shipping take?
Orders ship via USPS Priority within 1–2 business days, and the average transit time to the continental U.S. is 3–5 days. Expedited options are available for an additional $15.
Can I return it if it doesn't fit?
Returns are accepted within 30 days of receipt provided the items are in original condition. Polymer parts must be unaltered; once drilled, the lower is non‑returnable per federal law.
Does this work with a standard AR‑15 trigger group?
The RL556V3 lower is drilled to accept a standard Mil‑Spec trigger group. Installation requires a 7‑mm drill for the trigger pin and a 14‑mm hole for the safety selector.
Sources & methodology. Editorial review and rating by Derek M. Harlow based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-05-09.
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