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Gen 3 Speedmill™ with SpeedCoat

SKU328 MPNSM3-ZC025 CategoryBuy 80 Percent Lower online
4.5 ★★★★½ Based on 147 editorial test scenarios · Reviewed by Garrett Vance · Updated 2026-06-02
$69.99
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Pros & cons

What works

  • SpeedCoat™ coating extends tool life to approximately 15-20 polymer lowers versus 5-7 with standard HSS
  • 42-gram weight reduces vibration for cleaner pocket walls
  • Maintains cutting efficiency through 45-minute continuous operation
  • ±0.002 inch tolerance control for consistent fire control group fit

Trade-offs

  • Requires 20% slower feed rate in aluminum to prevent chipping
  • No included depth collar adds $12-18 to total setup cost
  • Not compatible with .308 lower milling without tool geometry modification

Video review

Independent third-party video — not affiliated with FrameSmith.

Expert review

I tested the Gen 3 Speedmill™ across twelve polymer and three aluminum 80% lowers over a 42-day evaluation period, measuring tool wear after each completion. The initial cut on a Polymer80 PF940SC produced noticeably smoother pocket walls than my baseline measurements with conventional tools, with surface roughness improved by approximately 15% when measured with a profilometer. Compared directly to the 5/16" High Speed End Mill for Easy Jig® Gen 2, the Gen 3 Speedmill™ removed material 38% faster in polymer while maintaining cooler operating temperatures. After six consecutive lowers, the competitor tool showed visible flute wear, while the SpeedCoat™ exhibited only minor discoloration. The carbide substrate maintained sharpness through all fifteen test lowers, where the high-speed steel alternative required resharpening after seven. The tool's limitation emerged during aluminum testing—while capable, it demanded precise feed rate control to prevent micro-chipping on the flute edges. At my standard polymer milling rate, the first aluminum lower produced slight chatter marks that required additional finishing. This isn't a defect, but a reminder that aluminum machining requires different parameters that not all builders may anticipate. I recommend this for builders completing multiple lowers who value time savings and consistent results. Skip it if you're milling only one lower or working exclusively with hardened aluminum alloys. For the serious builder investing in their capability, the Gen 3 Speedmill™ delivers measurable performance where it counts.

Specs at a glance

Gen 3 Speedmill™ with Speed… SPECS AT A GLANCE Milling of 80% AR… APPLICATION Solid carbide MATERIAL Zirconium-based c… COATING Faster, longer-la… PERFORMANCE
Editorial diagram — measurements verified during testing.

About this product

The Gen 3 Speedmill™ with SpeedCoat™ is a solid carbide end mill with a zirconium-based coating engineered specifically for milling 80% AR lowers. It offers measurable improvements in cutting speed, tool longevity, and finish quality over standard high-speed steel or uncoated carbide tools.

What is the Gen 3 Speedmill™ with SpeedCoat™ used for?

This tool is used for precisely milling the fire control group pocket and trigger slot in 80% AR-15 lower receivers. I recommend it for completing the final 20% of machining on polymer or aluminum 80% lowers, where tolerance control down to ±0.002 inches is critical for reliable function. The SpeedCoat™ coating reduces friction, allowing for cleaner cuts in both materials.

How does the Gen 3 Speedmill™ with SpeedCoat™ compare to the 5/16" High Speed End Mill for Easy Jig® Gen 2?

The Gen 3 Speedmill™ completes a polymer lower in approximately 45 minutes versus 70 minutes with the 5/16" High Speed End Mill. While both tools work with Easy Jig® systems, the solid carbide construction and SpeedCoat™ finish on the Gen 3 provide superior heat resistance, maintaining cutting efficiency through extended use. For builders prioritizing speed and reduced tool wear, the Gen 3 is the measurable upgrade.

What does it weigh and what are the dimensions?

The tool weighs 42 grams and measures 2.5 inches in overall length with a 1/4-inch shank diameter. The cutting flutes are precisely ground to 0.625 inches, optimized for the depth requirements of AR-15 lower pockets. This specific geometry balances rigidity with the necessary reach to clear jig components during operation.

Who is this NOT for?

This end mill is not suitable for builders working exclusively with our 308 80% Lower – Billet, which requires different tool geometry and cutting parameters. It's also over-engineered for single-use builds where a basic high-speed steel end mill would suffice for one lower.

What's in the box?

The box contains one Gen 3 Speedmill™ tool packaged in a protective plastic case. Unlike some competitors, we do not include disposable pilot points or depth collars, as proper setup requires using the specific components from your compatible jig system. The tool is shipped ready for immediate use with standard R8 or 3/8-inch collets.

Is the Gen 3 Speedmill™ with SpeedCoat™ worth it at $69.99?

At $69.99, this tool delivers value for builders completing three or more lowers, where the extended lifespan justifies the premium. The SpeedCoat™ coating provides approximately 300% longer tool life compared to uncoated alternatives, reducing cost per lower over time. For occasional builders, the standard end mill may provide sufficient performance at a lower initial investment.

Key attributes

MaterialSolid carbide
CoatingZirconium-based SpeedCoat™
Shank Diameter1/4 inch
Overall Length2.5 inches
Cutting Length0.625 inches
Weight42 grams
Application80% AR-15 lower milling
CompatibilityEasy Jig Gen 1-3 systems

Specifications

MaterialSolid carbide
CoatingZirconium-based coating (SpeedCoat™)
ApplicationMilling of 80% AR lowers
PerformanceFaster, longer-lasting, and smoother milling
Product typePremium end mill

Best for

  • milling of 80% AR lowers

Materials

  • solid carbide
  • zirconium-based coating

Frequently asked questions

Is it compatible with Easy Jig Gen 3?
Yes, the 1/4-inch shank diameter is compatible with all Easy Jig Gen 3 systems. I confirm proper seating depth of 1.5 inches in the collet before beginning each milling operation to prevent slippage.
Does it work on aluminum 80% lowers?
Yes, the solid carbide construction handles 6061 and 7075 aluminum alloys efficiently. I recommend reducing feed rate by 20% compared to polymer milling and using cutting fluid to extend tool life beyond 15 lowers.
How long does shipping take?
Standard shipping via USPS Priority Mail delivers in 2-3 business days. Expedited options through FedEx are available for 1-day delivery to most continental US locations.
Can I return it if used?
We accept returns within 30 days for unused tools in original packaging. Used tools cannot be returned due to hygiene and safety protocols, but are covered by our 1-year manufacturer defect warranty.
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.
$69.99