Mag extensions

I recently purchased a couple of mag extensions for my newer Glock 21 mags, (the straight cuts on the back top of the mags vs the round cut), and no matter how hard I push with my Glock loader, none of the mag extension mags will accept more than 28 rounds before bottoming out, leaving the last two bottom holes in the extension showing empty. Anyone had this problem? Cut the mag spring help?
Thanks to all.

Haha yeah. First of all chuck the glock loader in the trash. Then go buy a UPLULA. The glock loader will break on you.

The current Magex now come with a thicker gauge spring. I have the U-notch preban mags which are non drop free and partially metal lined. The mag body swells when it is fully loaded with bullets. The follower has a tendency to snag on the inside right where the mag body and extension meet. I called Kriss to see if they might have come across this and the guy I spoke with said no. But he told me that they now have a thicker gauge spring and that might solve the problem I was having.

I got a new spring but still have the problem. So I will need to shave a little bit of the mag and see if that helps.

anyway use the uplula. it works really really well.

Yeah, I bent the Glock loader but still can feel the hang-up.
Thanks for the good advice. I guess it's time to get the dremel tool/file out and shave where the extension meets the mag.

alcat wrote:Yeah, I bent the Glock loader but still can feel the hang-up.
Thanks for the good advice. I guess it's time to get the dremel tool/file out and shave where the extension meets the mag.

Dont do that, I am only resorting to that due to my specific problem. Im using U-notch preban mags. They dont work reliably with the mag extension.

You should have no problems with your post ban mags. It is just getting those last two rounds os tough. You shouldnt need to dremel anything.

Gotcha! Just wish I could feed a full 30. I am leavng my mags full to try to break in the springs. Hopefully that will help.
Thanks again.

Yeah I can get 29 in two of my mags and only 28 in the other. I guess I wish they'd all hold 30 but 28-29 rounds of .45 is still kickazz!

ItsAllCreated wrote:Yeah I can get 29 in two of my mags and only 28 in the other. I guess I wish they'd all hold 30 but 28-29 rounds of .45 is still kickazz!

I just went shooting today and tried to fit 30 in my extension. No joy. I tried to push down on the extension with the UPLULA and it doesnt like it. Also my u-notch preban feed lips dont like the spring. It double feeds the Kriss. So I may need to look into a square notch preban and use the older spring to fit 30. I know I have fed 30 rds in the old magex spring.

anyone ever tried those aftermarket 27rd mags like the ones they sell in cabellas? would you guys recommend staying away from those and sticking to glock 13rds plus the 17 extension?

Well since NY has a mag limit of 10rds, we can't use those. But as you say you are LE that is different. I would stick with 13rd post ban with extension.

I have 3 mags with KRISS extension kit all 3 mags only load 28 rounds

I have 3 27 rounds aftermarket mags 2 of them are the same and one of those
Will FTFeed. I ll post some pics of them later

Both aftermarket mags will load 27 rounds and the glock with KRISS extension will load 28 easy.

I believe the aftermarket mags are the same just that the one on the bottom is a older model.

SGM Tactical 27 Round Extended Glock 21 Magazine
http://www.cheaperthandirt.com/2MGSGMTGL2127-1.html

Also called KCI Glock 45 ACP Magazine 27 Round
http://www.cheaperthandirt.com/MAG735-1.html

Manufacturer: Red White and Blue
http://www.galatiinternational.com/product/LCG4526.html
and http://www.kyimports.com/index.php?main_page=product_info&cPath=1_2_3&products_id=388

The "new" KRISS USA store has changed up the naming a bit on the MagEx extended kits and magazines They are now called "MagEx 25+ Extension Kit for Glock21". So, this looks a lot like "your mileage may vary" in capacity... it will be at least 25... but we're not going to say 30 anymore. As others in the thread have noted, it is going to be a spring difference.

http://store.kriss-usa.com/accessories/magazines.html

I think they are just covering their asses because we are complaining about not holding 30 rds. I say buy a spare extension spring and experiment with removing a couple coils.

I would offer that it's more of "lessons learned" over time where yeah, they were able to get to 30 rounds in the original design (original spring specs), but as the spring weakened it would perhaps not feed the first round (or more) off the top of the maxed mag reliably. I'm willing to live with a stronger spring ("revised specs") and slightly reduced round count if it feeds all of them 100% all of the time... over time.

Hmm. Perhaps i should try the upgraded spring. I have one. But i put the original back in for round count. I suppose they have their reasons for upgrading the round count.

smurf24k wrote:anyone ever tried those aftermarket 27rd mags like the ones they sell in cabellas? would you guys recommend staying away from those and sticking to glock 13rds plus the 17 extension?

Here is an aftermarket Glock .45 hi-cap review thread that touches on some of the pros/cons (and appears to be updated over time):
http://www.glocktalk.com/forums/showpost.php?p=18994504&postcount=4

mambro wrote:Here is an aftermarket Glock .45 hi-cap review thread that touches on some of the pros/cons (and appears to be updated over time):
http://www.glocktalk.com/forums/showpost.php?p=18994504&postcount=4

I contacted the author of that GlockTalk post (GRT45) about what we are seeing with the MagEx capacity at 28 rounds and he had some very interesting feedback on his personal MagEx experiences:

I purchased the heavier gauge (1.6mm dia) MagEx spring last Feb for evaluation.

I'm in a quandary on how to represent the capacity of the MagEx unit now because I'm able to routinely load it to 30 rounds with the new spring and it functions reliably in my G30SF 45ACP pistol.

I do some preparation of the MagEx spring before installing it to align the coils and wipe the interior down with a silicone cloth. Before assembly, I heat the locking tabs of the MagEx and insert a knife blade under them to force them outward while they cool in place. That eliminates binding of the spring and tabs on the interior when the spring is fully compressed. In my past experience, it can be the difference between loading 28 rounds and the full 30. Of course, I always use the UpLULA to load the MagEx.

I believe the heating was mentioned in a different thread as being done with a hair dryer for about 1 minute.

what heat the mag before you load it ?

CatMostFeared wrote:what heat the mag before you load it ?

No, when assembling the MagEx and the G21 into the 30-rd mag.

Ok with regards to the Mag extension, here is one reason why it doesn't work as reliably in other mags than the post ban.

The Post ban 13rd mag has a bevel on the leading inside edge of the mag.

From L-R: Postban 13rd, Postban 10rd, Preban FML 13rd, Preban NFML 13rd




As you can see, the Post ban 13 rd mag has a bevel. The 10 rd cant use extensions legally so I didn't bother. The FML (full metal lined) square notch 13 rd mag has been modified. I made my own bevel using a sharp knife. The U-notch NFML (non full metal lined) preban 13rd mag does not have this bevel.

When i used my preban mags with the extension, the follower would get stuck halfway up the mag and stop feeding rounds. I thought maybe a full metal lined mag would solve the problems so i bought the square notch. However I had the same problems. then i came to the realization that the mag needs to be trimmed so the follower doesn't snag. I never bothered to look at my post ban mags until recently.


Here is a picture of all 4 mag bodies.


Close up of the notches. I modified the square notch a little because it was interfering with the KRISS bolt.

CatMostFeared wrote:Both aftermarket mags will load 27 rounds and the glock with KRISS extension will load 28 easy.

I believe the aftermarket mags are the same just that the one on the bottom is a older model.

SGM Tactical 27 Round Extended Glock 21 Magazine
http://www.cheaperthandirt.com/2MGSGMTGL2127-1.html

Also called KCI Glock 45 ACP Magazine 27 Round
http://www.cheaperthandirt.com/MAG735-1.html

Manufacturer: Red White and Blue
http://www.galatiinternational.com/product/LCG4526.html
and http://www.kyimports.com/index.php?main_page=product_info&cPath=1_2_3&products_id=388

That mag pictured on the bottom is the Asian Military version. I have not had good luck with those at all. In fact, the floor plate is weak and can pop out causing rounds to suddenly eject out of the bottom of the mag. The spring is suspect and can cause mis-feeds (especially if you load more than 20 rounds). I now only use the true Glock 21 mags (metal lined, suare notch, 13 rnds) with the KRISS extensions (pictured on the top).

I have 2 of the bottom ones and both will fail to feed on the last 2 rounds out of 27

welcome to the site RJinAZ

There is an easy quick fix to the asian mags! Take off the bottom plate and lock plate and replace with original Glock parts and they work great. No more popping apart. The mag bodies are identical to Glocks as to the floorplate mounting. I haven't had any come apart since the fix. Worked for me.

I have the same problem with my Beretta 92 extended Mag (30 Rds); can fit around 28 and then its tapped out. Don't want to really bear down and break my UpLULA loader or hurt myself. On the plus side; half full mags are more fun for "run and gun" maneuvers since you get to work the gun with mag changes and so forth.

Just my $.02's