Polymer80 P80-JIG-RL556v3 Jig Kit
- Firearms ship to the FFL dealer you choose, in any state
- Free shipping on orders over $99 · ships in 1–2 business days
- 30-day returns on unused parts and accessories
About this product
The Polymer80 P80-JIG-RL556v3 Jig Kit is a Gen 3 fixture system for converting AR-platform 80% lower receivers into functional firearms. This kit contains all necessary drill plates, router base plates, and tooling bushings required for a complete milling operation. It represents the third evolution of Polymer80's fixture design, incorporating learned tolerances from thousands of builders' feedback.
What is the Polymer80 P80-JIG-RL556v3 Jig Kit used for?
The jig kit is used to precisely mill the fire control group pocket, trigger pin holes, and selector lever detent slot in an 80% lower receiver. Specifically, it aligns your router or drill press to cut 0.154-inch diameter trigger and hammer pin holes to a depth of 0.850 inches with a positional tolerance of ±0.002 inches. It converts an inert forging into a serialized-compliant firearm component in approximately 45 minutes of machine time.
How does the Polymer80 P80-JIG-RL556v3 Jig Kit compare to the 80% .308 Easy Jig® Gen 1?
The P80-JIG-RL556v3 offers better material support and finer adjustment than the older Gen 1 jig for AR-10/.308 platforms. The Gen 3 design uses six clamping points per side versus four on the Gen 1, reducing workpiece flex during the 0.200-inch deep fire control pocket milling operation. For LR-308 builds, the newer jig provides superior wall support, but for a dedicated .308 build, you may consider a dedicated 308 80% Lower – Billet for maximum rigidity.
What does it weigh and what are the dimensions?
The complete kit weighs 5.2 pounds (2.36 kg), with the primary aluminum jig block accounting for 3.8 pounds of that mass. Its assembled external dimensions are 9.25 inches long, 4.75 inches wide, and 3.10 inches tall. When disassembled for storage, the largest component—the main plate—measures 7.50 by 4.75 by 1.25 inches.
Who is this NOT for?
This kit is not for builders working with pistol-caliber carbine (PCC) lowers that use a different magazine well geometry, nor is it for builders seeking a fully guided solution that requires zero measurement. You must still verify critical depths like the 1.250-inch buffer tube thread engagement, a process detailed in our guide on How to Check 80% Lower Receiver Buffer Tube Threads with Machinist-Grade Precision.
What's in the box?
The box contains one 6061-T6 aluminum main jig block, three drill guide plates (for AR-15, LR-308, and AR-9), one router base plate, four tool steel drill bushings, and twelve M4-0.7 x 16mm socket head cap screws. You do not receive an end mill; that must be sourced separately, such as the 5/16" High Speed End Mill for Easy Jig® Gen 2, which is cross-compatible.
Is the Polymer80 P80-JIG-RL556v3 Jig Kit worth it at $50.99?
At $50.99, the kit is worth the cost if you plan to build more than one AR-platform lower, as it amortizes the fixture cost across multiple receivers. The lifetime warranty on the aluminum components provides long-term value, protecting against guide bushing wear over an estimated 15-20 lower milling cycles. Compared to purchasing individual drill jigs for each platform, this multi-platform kit consolidates three tools into one for a 60% reduction in fixture cost per platform.