Stern Glock Adapter in RDB CMMG

[JDIllon]

For those of you that might want to run Glock mags in your RDB that uses the CMMG AR / endomags. I have a 200/Banshee 9mm

and have been running it with the Stern Glock adapter. I took off the ejector and the bolt hold open! And the adapter works? Mine ran just fine with all of my Glock factory mags! With the Asian mags and KCI Glock knock offs, I had to file a little off of the left rear corner of the feed lips so the bolt would clear it.  I checked and that change didn’t affect how those mags worked in my regular PCCs. JD 
NOTE: Stern does NOT recommend this modification .

[spd522]

I friend of mine has the Stern adapter and loves it.   He said he hasn't had a single issue and uses it often for range instruction.   I picked up one of the Sylvan adapters a while back and finally tried it out.  I loaded up a few different Glock mags with an assortment of reloads and factory ammo.  The gun ran just fine.  I did have to try a couple of different lowers as it  fit all but  the ones I had coated via a rattle can from Lauer.   But the ones it fit in it ran 100%.  I am not crazy about the mag release lever in front of the mag but it does work smoothly and quickly as intended so it's more of a training issue I will need to work on.    I am glad companies have designed these vs having to get a dedicated lower.    I have considered the Stern for the M&P/ P320 mags as well for a stubby HD pistol build.  I have a supply of mags for both.

 

[MoRivera]

Interesting...there does seem to be some leeway as to how high the Stern adapter sits in the mag well, ands it has those adjustment set screws.  Tempted to try it out but want to leave my Stern for other receivers I have.

Edited January 19, 2021 by MoRivera

[JDIllon]

It takes 5 minutes to take off the ejector and bolt hold open. There really isn’t any slop if you install it according to the instructions. It gets locked into the magwell with the AR mag release. And snugged down with the set screws. I have installed it in 4 different guns including a Colt SP1 full auto. It works great in all of them. JD 

[MoRivera]

On 1/19/2021 at 6:42 PM, JDIllon said:

It takes 5 minutes to take off the ejector and bolt hold open. There really isn’t any slop if you install it according to the instructions. It gets locked into the magwell with the AR mag release. And snugged down with the set screws. I have installed it in 4 different guns including a Colt SP1 full auto. It works great in all of them. JD 

Oh I've had mine for years and it's worked like a champ with my regular blowback uppers.  Maybe I will give it a shot with my CMMG RDB upper.  But the only time I would even need that is when shooting falling steel where I'd get 33+ rounds from a Glock mag as opposed to just 30 using a P-Mag with the CMMG Endomag inserts.....and since it looks like I'll be laying low from shooting for a while with this ammo crisis, there's no rush. 

 

So you just inserted and set like you would if using with a regular blowback upper?  Or did you specifically set it higher or lower in the mag well before tightening the set screws?

Edited January 22, 2021 by MoRivera

[JDIllon]

You have to take off ejector and bolt hold open. Takes about 5 minutes. Put it in pull it down st it just like you do now. If you want real fire power? Buy KCI 9mm drum for Glock setups. It is fantastic really easy to load, has a 2finger ratchet thing on the mag. JD