JMT 80% Lower Receiver for AR-15 with Jig


JMT 80% Lower Receiver for AR-15 with Jig

5.00 out of 5 based on 3 customer ratings
3 customer reviews

$94.00 $70.00

Color :
Clear selection
  • Made from hybrid polymers that won’t corrode like aluminum
  • Includes jig with machining instructions
  • 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


To see this entire video head over to our YouTube channel.

For JMT’s machining guide, click here.

SKU: N/A Categories: ,


After much research in polymer 80% lower receivers, James Madison Tactical has created its own formula of hybrid polymers and fibers with additional reinforcements in high stress areas to bring you the best AR-15 lower receiver on the market today.

All of our 80% lower receivers are engineered to Mil Spec tolerances and because it is fashioned from extremely durable fiber polymer materials there are no concerns about corrosion as you may find in aluminum AR-15 lower receivers.

Additional information

Weight 1.2 lbs
Dimensions 10 × 6.5 × 2.2 in

JMT (James Madison Tactical)


Black, Olive Drab Green

3 reviews for JMT 80% Lower Receiver for AR-15 with Jig

  1. Greg Adams

    I have done a couple of these JMT lowers now and have very good results. Even though I am doing my work on a CNC milling machine the jig that is provided is outstanding. I use the jig, which on the outside has flat even surfaces, so I can easily hold the jig and receiver in my milling vise. I can see how easy it would be to use the provided jig if you only had a simple drilling press. With the use of a correct end mill bit in your drill press anyone should be able to do one of these 80% lowers.

  2. Jim (verified owner)

    I ordered 2 more of the JMT lowers, I just finished my first one, using a drill press with an x-y slide. If you follow the jig, keep your speed at or just under 800 rpm, you will have an awesome receiver, results are way better than polymer80, by far..

  3. Chris H (verified owner)

    Was always a little curious about an ar pistol build using a polymer lower. I mean i wouldn’t go under 10 ” barrel because of the substantial increase of pressures but in my build i went nuts to see what this thing could do . specs- super42 in h2 config – JMT OD green lower , AP m4ea1 upper/9 in rail combo , and a Seekins match grade 223 Wylde 10.5in barrel ,my custom trigger and add the great ship times/price and service from Bullet Central and I sport a tack driver at 200yds plus that raises eyebrows at the range that has yet to fail me….What more can you ask for …

Add a review

Your email address will not be published.

Join Waitlist We will inform you when the product arrives in stock. Just leave your valid email address below.
Email Quantity We won't share your address with anybody else.