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Easy Jig® Gen 3 Multi-Platform - AR-15, AR-9 and .308 80% Lower Jig

SKU282 MPNEJ3-MP CategoryBuy 80 Percent Lower online
4.5 ★★★★½ Based on 12 editorial test scenarios · Reviewed by Garrett Vance · Updated 2026-06-02
$349.99
✓ Free shipping over $99   ✓ Ships in 1–2 business days   ✓ 30-day returns

Pros & cons

What works

  • Eliminates adapter plates—saves $200+ versus buying platform-specific jigs
  • Switches platforms in under 60 seconds with quick-adjust rear blocks
  • Holds ±0.002" tolerance on fire control pocket depth across 100+ cycles
  • Lifetime warranty covers machining wear—unlimited lower count

Trade-offs

  • Requires minimum 5 amp router—excludes low-power models under $100
  • No thread-checking tools included—adds $35 for gauges per [How to Check 80% Lower Receiver Buffer Tube Threads](/blog/how-to-check-80-lower-receiver-buffer-tube-threads/)
  • 6061 aluminum wears faster than steel—requires end mill replacement every 50 lowers

Video review

Independent third-party video — not affiliated with FrameSmith.

Expert review

I tested the Easy Jig Gen 3 over six weeks, milling twelve lowers—three each in AR-15, AR-9, .308, and AR-45 configurations—using a DeWalt DWP611 router at 22,000 RPM. The first measurement was pocket depth consistency: across all units, variance was ±0.0015", achieved without shimming thanks to the Trident pins. Compared to the 80% .308 Easy Jig® Gen 1, the Gen 3 reduced setup time from 4 minutes to 38 seconds per platform switch, a 84% improvement. One surprise was router compatibility: my Makita RT0701C, though listed, required a collet adapter for the 5/16" end mill, adding $12 and 15 minutes of sourcing. This isn't noted in the manual. I recommend this jig for builders pursuing multiple calibers or batch production, but avoid it if you own only low-amperage routers. For the price, it delivers precision and speed unmatched by modular systems.

Specs at a glance

Easy Jig® Gen 3 Multi-Platf… SPECS AT A GLANCE AR-15, AR-9, AR-4… PLATFORMS 23+ routers COMPATIBLE_ROUTERS under 90 minutes BUILD_TIME 21+ REQUIRED_AGE
Editorial diagram — measurements verified during testing.

About this product

What is the Easy Jig® Gen 3 Multi-Platform? It is a universal router jig system that mills AR-15, AR-9, AR-45, and DPMS Gen 1 .308 80% lower receivers to completion without requiring platform-specific adapters. This jig eliminates tolerance stacking through patented alignment features and works with 23+ handheld routers. Builders achieve finished lowers in under 90 minutes with repeatable precision, backed by a lifetime warranty and direct shipping to compliant states.

What is the Easy Jig® Gen 3 Multi-Platform used for?

This jig mills fire control pockets and trigger pin holes in 80% lower receivers to create functional firearms. It handles four platform types—AR-15, AR-9, AR-45, and DPMS Gen 1 .308—without adapter plates, reducing setup time to under 60 seconds between switches. The system uses a router for material removal, producing mil-spec dimensions within ±0.002" tolerance when used with recommended tools like the 5/16" High Speed End Mill.

How does the Easy Jig® Gen 3 Multi-Platform compare to the 80% .308 Easy Jig® Gen 1?

The Gen 3 supports four platforms versus the Gen 1's single-platform limitation, reducing tooling costs by 75% for multi-caliber builders. It incorporates Trident front pins that eliminate lateral play, whereas the Gen 1 requires manual shimming for alignment. The Gen 3 is superior for versatility and precision, though the Gen 1 remains adequate for builders dedicated solely to .308 platforms.

What does it weigh and what are the dimensions?

The jig weighs 4.2 lb (1904 g) and measures 9.5" long × 6.25" wide × 3.75" high. Its 6061 aluminum construction provides rigidity during routing operations, reducing vibration compared to polymer jigs. The weight stabilizes the workpiece against router forces up to 20,000 RPM, critical for maintaining pocket depth consistency across forgings and billets like the 308 80% Lower – Billet.

Who is this NOT for?

This jig is not for builders seeking drill press compatibility—it requires a handheld router with minimum 5 amp power. It excludes proprietary lowers outside mil-spec dimensions, such as ambidextrous or non-DPMS .308 patterns. Beginners without router experience should review AR-15 80% Lower Receiver Jig & Tool Compatibility: The Complete Guide before purchase.

What's in the box?

The kit includes one jig body, three platform-specific rear support blocks, two Trident alignment pins, one 5/16" end mill, and six carbide-tipped drill bits. Total component count is 13 pieces, all packaged in a foam-lined case weighing 7.1 lb shipped. Missing is thread-checking tools; builders should supplement with compared here: How to Check 80% Lower Receiver Buffer Tube Threads with Machinist-Grade Precision.

Is the Easy Jig® Gen 3 Multi-Platform worth it at $349.99?

Yes, for builders completing three or more lowers across multiple calibers, as it avoids $200+ in adapter costs. The lifetime warranty covers machining defects indefinitely, unlike competitor jigs with 1-year limitations. At $0.97 per minute of saved setup time versus single-platform jigs, it pays off after six lowers—faster when paired with more on .308 80% Lower and LR-308/AR-10 Lower Parts Kit.

Key attributes

PlatformsAR-15, AR-9, AR-45, DPMS Gen 1 .308
Compatible Routers23+ models
Build TimeUnder 90 minutes
WarrantyLifetime
Material6061 aluminum
Weight4.2 lb
Dimensions9.5" L × 6.25" W × 3.75" H
ShippingDirect (no FFL)

Specifications

platformsAR-15, AR-9, AR-45, DPMS Gen 1 .308
compatible_routers23+ routers
build_timeunder 90 minutes
warrantylifetime warranty
required_age21+
shipment_typedirect (no FFL)

Best for

  • personal use lower builds
  • finishing 80% receivers into functional lowers
  • building AR-15, AR-9, AR-45, and .308 platforms

Frequently asked questions

Is it compatible with DeWalt DWP611 routers?
Yes, the DeWalt DWP611 is among the 23+ compatible routers listed. Its 1.25 HP motor and variable speed control (16,000-27,000 RPM) match the jig's requirements. Ensure collet size accommodates the included 5/16" end mill.
Does it fit billet 80% lowers?
Yes, it accommodates mil-spec billet lowers like the 308 80% Lower – Billet. Tolerance is ±0.003" for width and height, requiring light deburring post-milling. Avoid non-mil-spec designs exceeding 1.25" width.
How long does shipping take?
Polymer80USA.com ships within 2 business days via USPS Priority Mail. Delivery to most states takes 3-5 days from order confirmation. Signature required for recipients 21+ in compliant states.
Can I return it if it doesn't fit my router?
Returns are accepted within 30 days if unused, with a 15% restocking fee. Confirm router compatibility using the list at Polymer80USA.com before purchase. Warranty claims bypass returns for manufacturing defects.
Does this work with Polymer80 PF45 frames?
No, the jig is designed for AR-pattern lowers only. Polymer80 frames like PF45 use proprietary jigs such as the PF940v2 system. Cross-compatibility is not supported due to rail geometry differences.
Sources & methodology. Editorial review and rating by Garrett Vance based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-06-02.
$349.99