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JMT AR-15 Gen 2 80% Polymer Lower with Jig and Mil-Spec AR15 Lower Parts Kit - Black

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Now: $124.99
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Old commercials used to boast about their products being made out of "space-age polymer." Well, it's not space-age, but polymer is definitely still something to boast about. In the case of your next 80% lower receiver, it's lighter, easier to cut into and mill out, and just as tough as mil-spec aluminum lowers. We want to help you build your next space gun, not only by giving you James Madison Tactical's Gen 2 polymer 80% lower with the necessary jig, but we also packaged a mil-spec lower parts kit in it too.

The James Madison Tactical AR-15 Gen 2 80% Polymer Lower with Jig

Worried that a polymer lower receiver isn’t up to the task of handling your AR’s constant abuse? We’re excited to bring in the new Gen 2 Polymer 80% Lower from James Madison Tactical! This ultralight JMT lower includes the necessary 80% jig for cutting and drilling the fire control cavity, and it includes beefed up designs and upgrades to ensure it’s truly battle-ready. 

Stronger, Tougher Polymer

JMT took extra time to develop their reinforced polymer for this new 80% lower. Engineers incorporated a way tougher polymer-fiber construction that can withstand rapid fire, high heat, and the rigors of the high impacts, the hunt, or any 3-gun competition.

Parts Compatibility

Considered 100% mil-spec, this ar 15 polymer lower is compatible with any “retail” AR components, including standard LPKs, buffers, and grips. JMT even cut the mag well to perfectly match your favorite Magpul magazines.

Upgraded Features:

  • Extended upper fire control box sections.
  • Upper left magazine well box section.
  • Webbed magazine wells match Magpul mags.
  • Extended bolt release roll pin posts.
  • New JMT Gen2 logo markings.

Manufacturer instructions can be found here.

No FFL is required to purchase this lower receiver. This polymer 80% lower receiver is not considered a firearm and is compliant with ATF receiver blank determinations (Gun Control Act of 1968). Not classified as a firearm as defined in 18 U.S.C. 921(a)(3).

The Mil-Spec AR-15 Lower Parts Kit

Want an AR-15 trigger that suffers no creep, take-up, or over-travel? Looking for the easiest-to-install LPK? How about the most affordable parts kit possible? The mil-spec AR-15 LPK comes in at a low-price with machining and performance that truly feels match-grade.

Perfectly Polished for Performance

Th quality control is second to none and the finish show it: Inside you’ll find a disconnector, hammer hook, and sear that were laser-cut and polished to break as clean as glass at exactly 4.5 pounds. The trigger affords perfect reset after every pull, with no break-in required. Every roll pin presses easily, while the hammer and trigger pins glide in with little effort.

Complete AR-15 Lower Parts Kit with Pistol Grip

This AR-15 Lower Parts Kit includes all components required for assembling your AR-15 stripped lower receiver:

  • Bolt Catch
  • Bolt Catch Plunger
  • Bolt Catch Roll Pin
  • Bolt Catch Spring
  • Buffer Retainer
  • Buffer Retainer Spring
  • Disconnector
  • Disconnect Spring
  • Steel Hammer
  • Hammer Pin
  • Hammer Spring
  • Magazine Catch
  • Magazine Catch Button
  • Magazine Catch Spring
  • Pistol Grip (A2 style)
  • Pistol Grip Lock Washer
  • Pistol Grip Screw
  • Pivot Pin
  • Pivot Pin Detent
  • Pivot Pin Detent Spring
  • Selector
  • Selector Detent
  • Selector Detent Spring
  • Takedown Pin
  • Takedown Pin Detent
  • Takedown Pin
  • Detent Spring
  • SSteel Trigger
  • Trigger Guard
  • Trigger Guard Roll Pin
  • Trigger Pin
  • Trigger Spring

Easy-to-Follow Install Instructions

First time assembling, or need assistance with certain steps? Check out our in-depth instructional and picture guide. It shows the full LPK assembly with tips and tricks, including tools required and the buffer tube and castle nut install.

Need more help or detailed steps? Watch our in-depth instructional video here!

WARNING: Handling firearms parts and accessories can expose you to lead and other petroleum products known to the State of California to cause cancer and reproductive harm. For more information go to:

Shipping Restrictions

Shipping of various parts and/or accessories are prohibited to states and locales (ie New Jersey, California, New York, etc…) with restrictions against certain parts and/or accessories or "assault weapons" (i.e. states with high-capacity magazine restrictions, manufacturing of semi-automatic weapons, etc..). It is your responsibility to be aware of your local firearms laws before purchasing from our website or machining a firearm. We try our best to keep our shipping page current, but laws change daily. only ships within the United States. Federal legislation dictates we cannot ship our products internationally.

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James Madison Tactical

We are a national retailer of individual components and not all products depicted on this website are legal in every state. Shipping of various products found on this website are prohibited to some states (such as California, Connecticut, District of Columbia, Hawaii, New Jersey, New York, Rhode Island, and Washington). The information, pictures, text or products presented on this website are not a representation by us, and should not be understood by you, that any product or completed firearm is legal to assemble or own in your state of residence. We encourage each and every builder to perform their own research about the state and federal laws that apply to them. It is your responsibility to understand the law and we encourage you to consult with an attorney or your local ATF representative.