When I saw the list of manufacturers attending Big 3 East Media Event, I did not know who Stern Defense was. I haven’t heard of them. I did a quick Google search and what I saw piqued my interest. They make an AR Glock Mag Adapter. We have seen Torkmag and ATI have their own Glock mag adapter however I have not seen the Torkmag in production and ATI was announced at SHOT Show. I could have sworn Strike Industries had a 3D printed prototype just before SHOT Show but I can’t seem to find it at the moment. Stern Defense is the new kid on the block. They only started making their Glock Mag Adapters four months ago. And not only do they have an adapter for Glock mags, they have come out with a mag adapter for Beretta 92 magazines, Smith & Wesson M&P and now M&P45.

As you can see below, there is a magazine release on the bottom right hand corner, oriented as if you are shooting the gun with the adapter installed. You push it with your index finger of your right hand.

If you are a left handed shooter, you can release the magazine with your right hand.

One nice thing about the Stern Defense mag adapter is that they do not require any removal of parts from your AR-15 lower. Colt pattern 9mm mag adapters typically require you to remove the bolt catch so it drop in from the top.  The Stern Defense mag adapter inserts from the bottom.

Once inserted you tighten this screw and the delrin block on the front face of the mag adapter pushes up against the inside of the magwell thus wedging the adapter in place.

Then you tighten the two small set screws you see along the bottom edge of the mag adapter. This prevents the mag adapter from shifting upwards.

You can see the glock mag over travel stop hits the cut out on the side of the mag adapter. The feed lip is extended just a bit and the top of the glock mag stops right below it also preventing over insertion of the magazine.

Here is the Glock mag adapter in my Salient Arms lower with Franklin Armory Binary Trigger.

The magazine adapter is compatible with a full auto lower.

Here is the Beretta 92 magazine adapter

Stern Defense had their S&W M&P45 mag adapter prototype at Big 3 East. They did mention that you need a heavy buffer. They are using an 11oz buffer. Another issue is you need to enlarge the ejection port of your AR-15. They used an upper for use with a .458 socom. Right now they are only held up by the barrels but once they square away the barrels they will be offering conversion kits and complete rifles.

The adapters are not cheap though. They are sold for $179.99 on Stern Defense’s website. You can get a dedicated 9mm AR lower for not that much more. A stripped 9mm AR lower can be bought for less. However you can use this in an existing lower. If you have an registered SBR lower or a full auto lower, then $179.99 is not that bad to be able to use Glock, Beretta or M&P magazines. For more information check out their website. We got one of the Glock mag adapters and one of their 9mm upper receivers on the way for a review. Keep a look out next month for that review.