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JMT Gen 2 Polymer 80% AR15 Lower Receiver & Jig

JMT Gen 2 Polymer 80% AR15 Lower Receiver & Jig

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James Madison Tactical Gen 2 80% Polymer Lower and Jig

The JMT 80% Carbon/long Fiber/polymer lower receiver is not to be compared with any other polymer lower on the market today. JMT has incorporated new material technology and manufacturing processes for enhanced durability, strength and reliability. The JMT 80% lower also comes with a specially designed 3-piece machining jig with every order. This allows the user to machine the JMT 80% polymer/composite fiber lower receiver with ease and precision using simple tools.

The first thing users will notice is the JMT 80% lower receiver looks beefed up from the outside and rightly so. JMT has managed to reinforce traditionally weak points found on other lower receivers offering the user a stronger lower receiver while keeping all of the required Mil Spec areas and attach points within Mil Spec tolerances. This permits smooth operations using a wide variety of Mil Spec and aftermarket accessories.

An enhanced mag well allows for use of many different magazines. No more concerns about whether your magazine is going to release when you push the magazine catch button. The JMT 80% polymer/fiber lower receiver features the latest in polymer/composite fiber technology along with sound engineering and (FEA) structural analysis. Reinforced longerons that run full span along the fire control pocket, over a molded metal threaded insert for pistol grip screw, reinforced butt stock mount, enhanced oversize trigger guard, reinforced flared mag well, forward magazine finger grate, enhanced gusseted forward upper receiver tabs, This is what makes the JMT 80% lower receiver superior to all others.


  • Extended upper fire control box sections
  • Upper left magazine well box section
  • Webbed magazine wells L & R side (matched for MagPul) magazines
  • Extended bolt release roll pin posts
  • New JMT Gen2 logo markings
  • Enhanced / oversized trigger guard
  • Reinforced upper forward pin tabs
  • Reinforced buttstock mount
  • Flared magazine receiver
  • Forward magazine finger grate
  • Compatible with metal AR-15 parts kit
  • Supports multiple calibers
  • Light weight
  • Will work on any upper receiver
  • Your purchase includes easy-to-follow instructions for completion of your JMT Polymer 80 to a fully functioning 100% lower receiver.

Additional Info

Additional Info

Manufacturer JMT
Finish No
Barrel Length No
Caliber No
Configuration No
Option No
Gas Length No
Height No
Rail Length No
Mount No
Profile No
Reticle No
Co Witness No
Size No


Customer Reviews (9)

No commentReview by R
So far so good. (Posted on 1/7/2017)
No commentReview by Joshua
- (Posted on 11/12/2016)
No commentReview by Bret
- (Posted on 11/8/2016)
No commentReview by Donna
i used a very good drill press and followed your instructions to the t, and ended up cutting too much material out of the well, and destroyed the unit. i was so pissed off that i ended up destroying the rest of it by cutting it into little pieces. a very fitting ending to the piece of shit that it was. i will never again waste that much money on a whim. no sir. (Posted on 10/26/2016)
No commentReview by Jose
- (Posted on 9/24/2016)
It's okayReview by TIMOTHY
Area that had to be machined out has porosity issues. If thru entire part I am worried about strength. Mag release had to be trimmed to allow release to move.
Take down pins need tool or bullet tip to reach and push in. Top area had slight amount that needed to be trimmed to allow rear take down pin holes to line up.
Video from JMT is for previous/different version and different, have to research and hope if it is your first one.
Only $15 less than Anderson lower and metal jig to do same thing. if doing 2 aluminum is cheaper. (Posted on 9/23/2016)
No commentReview by Albert
Not sure yet. Hope I have better fortune with these than I did on the last. My XY vise came loose from the table causing the bit to ruin the last one. (Posted on 9/1/2016)
No commentReview by Aaron
I haven't had the opportunity to finish the lowers so I can't give this a five star rating yet. Based on the feel and appearance of this product is can tell that it is made with high standards. (Posted on 8/16/2016)
No commentReview by Jonathan
- (Posted on 7/14/2016)

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