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
    Extremely well made

    Posted by Frank Perreault on Nov 14th 2021

    I was very happy with the build quality. It installed in the gun with no problems and worked like a charm. Couldn't be happier!

  • 5
    Ar-15 Mag Block for 9mm

    Posted by Gregory Lee on Oct 13th 2021

    This is a very high quality piece of equipment that works flawlessly. I will be purchasing another.

  • 5
    MAG-AD9

    Posted by Deez N. on Oct 9th 2021

    Solid construction and flawless function. Works perfect with the psa gen4 9mm upper. No jams or fuss with ets glock mags. Would definitely reccommend.

  • 5
    Ad9

    Posted by Steve on Aug 3rd 2021

    No brainer. If you're unsure of this product then you haven't been paying attention. Buy it. If you buy a dedicated lower it most likely won't have last round hold open

  • 5
    AR mag adapter 9mm/40 s&w

    Posted by Marion D Richardson on Jul 27th 2021

    Works great for 40 cal. Carbine and no malfunction after 500 rds, if you want to build a pcc this is the magwell adapter you need.

  • 5
    MAG AD9

    Posted by Max on Jul 27th 2021

    Product is perfect. Vinyl adjustment screws make it a great fit. More importantly the customer service is outstanding. Highly recommend.

  • 5
    MAG-AD9

    Posted by Duckstreet on Jul 27th 2021

    Works great!

  • 5
    MAG-AD9

    Posted by Robby T on Jul 14th 2021

    Great product. I put this in my lower using a PSA 9 upper with Glock style BCG, and went at it. No jams at all. I was using the SD HB1-H3 BUFFER and it cycled great. The bolt release was a little stiff at first, but after a couple of mag changes, it loosened up. If you don't want to buy a dedicated 9mm lower, this is a great product. It's also a bonus that you don't have to use an FFL, as you would with a lower.

  • 5
    Stern Defense MAG-AD9

    Posted by Racky on Jun 7th 2021

    Installed this in my Eagle Arms lower. Tactical Solutions 16” barrel. Faxon Bolt. Magpul GL-9 mags. This thing rocks ran like a sewing machine not one hiccup.