MAG-AD9

$179.99
(53 reviews) Write a Review
SKU:
001-SD MAG-AD9-GLOCK-9AND40-M

Mag-AD 9mm / .40 S&W Glock Magazine Adapter

Revolutionizing AR Builds. Designed, Machined, and Assembled in Our Factory.

The Mag-AD 9mm / .40 S&W Glock Magazine Adapter is Stern Defense’s flagship product, the one that put us on the map. Trusted by law enforcement and civilian gun enthusiasts alike, this adapter allows you to quickly convert your standard mil-spec AR-15, M4, or M16 lower assembly to accept Glock 9mm and .40 S&W magazines.

Crafted entirely in-house at our factory, every aspect of the Mag-AD is meticulously designed and built to ensure superior performance, quality, and precision. The adapter boasts a last round hold open feature, a breakthrough innovation that elevates the shooting experience—making it a must-have for anyone looking to enhance their AR build.


Why Choose the Mag-AD?

  • Quick Installation: Installs in seconds, transforming your AR-15 lower into a 9mm or .40 S&W Glock mag-compatible firearm
  • Last Round Hold Open: A critical feature for reliability and functionality, ideal for both law enforcement and civilian use
  • Lightweight & Ergonomic: Constructed from 6061 T6 aircraft-grade aluminum for optimal performance and comfort
  • Durable: Features a 4140 NiB-coated feed ramp and Type 3 hard coat anodization for wear resistance

⚙️ Technical Information

  • Material: Constructed from 6061 T6 aircraft-grade aluminum
  • Feed Ramp: 4140 NiB-coated for durability
  • Finish: Hard coat anodized Type 3 for maximum wear protection
  • Mag Release: Ergonomically designed for ease of use
  • Compatibility: Works with any mil-spec AR-15 lower receiver
  • Bolt and Barrel: Requires a 9mm or .40 S&W barrel (depending on caliber) and a Glock-cut bolt
  • Stock Components: All components remain stock, except for the bolt and barrel

⚠️ Important Notes


 Looking for a Complete Conversion Kit?

We’ve got you covered with everything you need to get started.


Transform Your AR Build Today

The Mag-AD 9mm / .40 S&W Glock Magazine Adapter is more than just a product—it’s an essential upgrade for anyone looking to get the most out of their AR-15 build. Whether you’re in law enforcement, competition shooting, or a civilian enthusiast, Stern Defense brings you the best in quality, performance, and reliability—all crafted right here in our factory.

53 Reviews Hide Reviews Show Reviews

  • 5
    Works Great

    Posted by Bobby on May 17th 2021

    Fits perfectly in my Anderson Hellfire lower. Highly recommend.

  • 5
    Stern 9mm conversion

    Posted by Mitchell Davis on May 4th 2021

    Easy install. Works great. Feeds great.

  • 5
    Excellent!

    Posted by Drew on Apr 26th 2021

    Cycles perfectly, once you set it up it stays in place through a tons of rounds, haven’t had to readjust since I got it!

  • 5
    MAG-AD9

    Posted by William Palacio on May 25th 2020

    There were 2 of this product one of them is from Stern Defense the MAG-AD9. After much search and compare its product. I found that the Stern was suited for my own liking compare to the other one I was looking into. When I finally received the MAG-AD9 I was impress if the quality that it's made from. I test fitted it I was happy with it glad I bought this from Stern. Great addition to my new AR9.

  • 5
    Mag Well Adapter - Am I nuts?

    Posted by RoCo on May 15th 2020

    First thoughts after unboxing. This thing costs more than some dedicated lowers. Am I nuts?
    After i popped this into my lower with a specialty trigger, I felt a whole lot better! This thing is real....and I didn't have to buy a new lower, or trigger, etc, etc.
    LRBHO is awesome. Fit and function are perfect.

  • 5
    MAG-AD9 Mod4 8.5 barrel.

    Posted by Lewis on May 15th 2020

    Received the MAG-AD9 and Mod4 9mm Upper yesterday. Put it on my BCM Pistol lower and ran 100 rounds through it. It was flawless!
    Going to get a designated lower for it so I can leave it assembled.

  • 5
    9mm mag well adapter

    Posted by Bernard on May 11th 2020

    Installed using instructions and it worked perfectly!

  • 5
    Very well engineered product

    Posted by Chris on May 6th 2020

    Very very nice product

  • 5
    Great product

    Posted by Evan Zimmerman on Jan 17th 2020

    Purchased the mag adapter. Dropped right in and works the way it is supposed to. Appears to be built very well. Bolt hold open feature is why I made the decision to purchase over others. Very impressed.