JE Machine Tech

JE4 AR 15 Lower Build Kit

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Now: $89.95
Was: $109.95



JE4 AR 15 Lower Build Kit

The JE4 AR 15 Lower Build Kit from Black Rifle Depot is the perfect solution for the lightweight and high-quality lower build. This kit includes a skeletonized Mil-spec stock, made in America, for a sleek and light look. The complete Mil-spec lower parts kit, also made in America, provides all the components you need to finish your lower build. The Mil-spec buffer tube kit, made in America, includes a 6-position aluminum receiver extension, 3 oz buffer, castle nut, end plate, and carbine spring. This kit is designed to meet the highest quality and performance standards and is backed by a lifetime warranty. Upgrade your AR 15 build with the JE4 AR 15 Lower Build Kit from Black Rifle Depot.


  • Includes Skeletonized Mil spec Stock (American Made)
  • Includes Complete Mil Spec Lower Parts Kit (American Made)
  • Includes Mil Spec Buffer Tube Kit (American Made)Lifetime Warranty 
    • 6-position 6061-T6 Aluminum Receiver Extension
    • 3 oz Buffer
    • Castle Nut & End Plate
    • Carbine Spring
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Warranty Information

This kit comes with our LIFETIME WARRANTY* in the rare case you need one. Each part is personally inspected for quality and hand packaged to ensure your satisfaction. *Note: Warranty only valid when used with mil-spec lower, warranty does not cover use with 80% lower.
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100 Reviews

  • 5

    Posted by Terry Einspahr on Apr 20th 2023

    Thank you so much for a great product!! The only issue I had was the trigger guard. I don't have an allen wrench that small. So it got put on the back burner till I get one!! The rest of the build was pretty easy and painless!! Thank you again.

  • 5

    Posted by Kyle on Dec 22nd 2022

    Everything you need to finish your stripped lower. Wish it came with a few more springs because we all know what happens sometimes, but it is a great lower

  • 4
    Lower parts kit

    Posted by Larry Gullett on Dec 22nd 2021

    Works just fine

  • 5
    It worked great to complete my build

    Posted by Sam on Nov 4th 2021

    Great price and fast shipping

  • 5
    It is great and fit perfectly and just what I needed to finish my first ar build

    Posted by Sam on Oct 21st 2021

    Will definitely be doing more business with black rifle depot again

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