I bought a dozen or so Glock 18 33rd mags from Midway USA and maxed them out for about 6 months to "set" the springs.

Upon unloading the mags, I noticed that every single mag had a problem where the cartridge wouldn't pop out. They were all jammed together. I tapped it a bit until one of them popped out. Sometimes the jam will be in the middle of the mag and I can dump out all the cartridges above it.

It seems like the springs are too weak. I have Winchester white box ammo and Brown Bear copper washed ammo. I think it may be a combination of "weak" mag springs and the copper washing (rougher than polished brass). However, this seems like a weak point in the 33rd mags since in the field, any resistance from rough cases or dirt/gunk inside the mag may cause similar problems as the springs get broken in.

What do you think? Do I need extra power 33rd mag springs? If so, which ones do I get?

I know what you're thinking, the Brown Bear crap is the problem. I heard that Glock 17s will basically eat anything and that is why I bought it. For reliability testing I have Brown Bear and Wolf ammo. My carry ammo and SHTF ammo is Winchester brass cased JHP. If I had been shooting with my 33rd mags, I'd probably have several failure to feeds - the slide wouldn't pick up anything since the rounds would have been jammed in the mag.

Are they factory Glock mags ?

Quoted: Are they factory Glock mags ?

Heck yeah, I bought them from MidwayUSA. They have the Glock 7151 +2 bottoms as well.

Mine have never malfunctioned, however, the spring does feel weaker in comparison to the 17/19. The cartridges may influence feeding from the mag if dirty or the finish isn't as "slick" such as a nickel case.
Check the spring, I had this happen once in a 17 mag where the spring bound into the follower(2-3 coils worth, causing the same problem you described(rounds seemed to be stuck in the mag body)

Hopefully this helps!

I'll check it out, but I'm not sure how I'd prevent it from happeningin the future other than trim the follower.

Dont store these loaded.

So every time you want to shoot a Glock 18 (either a MG sample or overseas) with the 33rd mags, you have to load them on the spot? That doesn't sound like something Glock would require. I heard that springs that get weakened by keeping mags loaded is a myth, and I haven't had a problem with my AR / AK / P90 mags. It's just the Glock 18 33rd mag w/ the Glock + 2 baseplate and #5 follower, FML, non-LEO marked.

Quoted: I bought a dozen or so Glock 18 33rd mags from Midway USA and maxed them out for about 6 months to "set" the springs. Upon unloading the mags, I noticed that every single mag had a problem where the cartridge wouldn't pop out. They were all jammed together. I tapped it a bit until one of them popped out. Sometimes the jam will be in the middle of the mag and I can dump out all the cartridges above it. It seems like the springs are too weak. I have Winchester white box ammo and Brown Bear copper washed ammo. I think it may be a combination of "weak" mag springs and the copper washing (rougher than polished brass). However, this seems like a weak point in the 33rd mags since in the field, any resistance from rough cases or dirt/gunk inside the mag may cause similar problems as the springs get broken in. What do you think? Do I need extra power 33rd mag springs? If so, which ones do I get? I know what you're thinking, the Brown Bear crap is the problem. I heard that Glock 17s will basically eat anything and that is why I bought it. For reliability testing I have Brown Bear and Wolf ammo. My carry ammo and SHTF ammo is Winchester brass cased JHP. If I had been shooting with my 33rd mags, I'd probably have several failure to feeds - the slide wouldn't pick up anything since the rounds would have been jammed in the mag.

Wait, I'm confused...

Are you saying that you haven't actually shot and experienced any failure to feeds with the 33rd mags? Because it sounds like, based on the statements in red, that you are just experiencing some binding in the mags when you manually unload them.

Pardon me if that is not the case but I wouldn't worry about it until you experience a FTE when actually shooting with the 33 rounders.

Heay suit your self. I would try keeping then 1/2 filled. I never kept all my mags fully loaded for my SW760. But that was a sumoi mag modified, and the steel in it was much more ridgid than the metal lined mags of the glock 33rd mags. Just so you know I too believe the spring weakening is BS. But Flexible mags stored in Texas heat fully loaded sounds like a lesson in frustration. Besides. The glock 18 was meant to be carried with a standard mag in it. Then the 33rd mags are inserted.

Those mags are a solution to a exotic (rare) problem. And as such their implementation will be (rare)exotic. The problem: When a gun runs at 11-13 rounds per second a 19 round mag only gives you 3 bursts. So feeding it as a avenue denial / suppressive fire roll was the birth of the 33 rd mag. Keeping these filled and out of a carrier pouch is gonna be hell to pay on the reliability. If you never get a jam from a 19 rd mag, it might stand to reason that you need to expect a jam or two out of the 30 rdrs.


12 of these laying around loaded for months on end = too heavy an expectation of zero FTF.

Do you know how hot a glock will be after three of these fast?? Well there better be a bucket of water near by, becuase the fourth one is gonna start getting painful.

M4arc: What does FTE's have to do with this? Basically once I stripped the top cartridge, the next cartridge does not pop up w/o significant slapping of the mag. If I had been using these mags at the range, I'd probably experience a failure to feed and probably spent half the time there wondering if I was limp wristing or doing something wrong.

I keep all of my AR, AK, and P90 mags fully loaded (30/30/50 respectively) and do not have a problem unloading all of the cartridges - they feed like butter. Obviously using only polished brass cased ammo is one possible solution since there's less friction. However, what happens to "Glock Perfection" when there's gunk inside the mag or if the cases are rough? I bought the Glock for its reliability and ability to shoot almost any type of new commercially loaded ammo.

If I have to keep these 33rd mags unloaded or only partially loaded, there's still no guarantee that they won't jam in the field. It seems to me that the 33rd mags need stronger springs because of the +2 baseplates.

1IV: you are right though, the 33rd mags seem to work fine if I load them up to around 15-20 rounds. Anything more, and it's hard to load the mag and jams frequently when unloading.

Quoted: M4arc: What does FTE's have to do with this? Basically once I stripped the top cartridge, the next cartridge does not pop up w/o significant slapping of the mag. If I had been using these mags at the range, I'd probably experience a failure to feed and probably spent half the time there wondering if I was limp wristing or doing something wrong. I keep all of my AR, AK, and P90 mags fully loaded (30/30/50 respectively) and do not have a problem unloading all of the cartridges - they feed like butter. Obviously using only polished brass cased ammo is one possible solution since there's less friction. However, what happens to "Glock Perfection" when there's gunk inside the mag or if the cases are rough? I bought the Glock for its reliability and ability to shoot almost any type of new commercially loaded ammo. If I have to keep these 33rd mags unloaded or only partially loaded, there's still no guarantee that they won't jam in the field. It seems to me that the 33rd mags need stronger springs because of the +2 baseplates. 1IV: you are right though, the 33rd mags seem to work fine if I load them up to around 15-20 rounds. Anything more, and it's hard to load the mag and jams frequently when unloading.

Sorry, I meant FTF.  Like I said, if you are doing this manually I wouldn't necessarily assume this would cause a FTF when the gun is actually firing. When is your next range trip?

Oh ok, that makes sense. I'm planning to head out to the range in about 2 months. Are you expecting the recoil of the pistol to "jar" loose the next round?

Quoted: Oh ok, that makes sense. I'm planning to head out to the range in about 2 months. Are you expecting the recoil of the pistol to "jar" loose the next round?

I'm thinking the extra pressure the slide puts on the mag spring when the mag is inserted may be the difference. I'll be interested to here how they work when you get them to the range.

2 months? Send me your G17 and mags and I'll take them out and test them for you this weekend

Quoted: Quoted: Oh ok, that makes sense. I'm planning to head out to the range in about 2 months. Are you expecting the recoil of the pistol to "jar" loose the next round? I'm thinking the extra pressure the slide puts on the mag spring when the mag is inserted may be the difference. I'll be interested to here how they work when you get them to the range. 2 months? Send me your G17 and mags and I'll take them out and test them for you this weekend

always scamming!

I didn't alter the follower, the spring did that once, never again. My 31/33 rounders never have malfunctioned.
take then apart, clean-check the spring-may be in backwards.

I decided to investigate further by unloading and re-loading all the Glock 18 mags and then cycling them through the G17 (without the striker of course!).

The Midway mags ALL experienced the same problem: After the first 1-7 rounds, nothing would pop up. There wasn't enough mag spring force to push up the rest of the rounds. Slapping the mag did nothing. I had to turn the glock upside down and slap it a few times so the rounds would move up. I could HEAR the mag spring "creak" as the rounds finally moved.

The G18 mags I bought from one of the AR15/GT vendors (I forgot his name but its one of those $25/G18 mag vendors) worked just fine with the Bear ammo! The rounds popped out like butter.

I'm way past Midway's return period and they're b/o'd. I've marked the mags so I can keep track once I install the Wolff +5% XP springs.

Do a mag test, remove the floor plate and the end of the spring should extend about 2 inches past the bottom.
If the springs do extend 2 inches, wipe the body out with oil and dry it out again. The steel can have parkerization on it that makes it bind. I know, we are not supposed to oil the mag inside ...but what do you have to loose?

If the springs are weak, install a regular mag floorplate and insert from a G17 mag. It might give you enough tension to work.

Quoted: Do a mag test, remove the floor plate and the end of the spring should extend about 2 inches past the bottom. If the springs do extend 2 inches, wipe the body out with oil and dry it out again. The steel can have parkerization on it that makes it bind. I know, we are not supposed to oil the mag inside ...but what do you have to loose? If the springs are weak, install a regular mag floorplate and insert from a G17 mag. It might give you enough tension to work.

The springs do extend 2" past the bottom of the mags. I have a gut feeling you are right regarding the extensions. However, I do not have regular floorplates for the 33rd mags since they came out of the wrapper with the 7151 +2 extensions and 7156 inserts. The cost of buying new standard floorplates and standard inserts is more than getting the Wolff +5% XP springs (dealer discount). I'll compare the suspected faulty mags, with some faulty mags that have the Wolff springs, against the "working" factory stock 33rd mags.

If you have access to the same generation G17 mags, those floorplates will work. I never had an issue with my G18 mags, 31rd non drop free to 33rd drop-free mags. I left them slightly underloaded, two rounds under maximum for longer than 6 months.

Maybe you follower or springs are binding, see if lubing one or two mags before your range outing might help.

Side question, how can you stay so long without shooting? I went to the range this Monday and already suffer severe withdrawal symptoms! Tomorrow I will be driven to the range by urgent desire.

The withdrawl symptoms are bad. I sometimes have frequent nightmares where my Glock does not work: slide doesn't return to battery, 9mm sub-compact is ejecting 45 Auto dummy rounds, and failures to feed. The most recent nightmare persuaded me to check out my mags.

Quoted: The withdrawl symptoms are bad. I sometimes have frequent nightmares where my Glock does not work: slide doesn't return to battery, 9mm sub-compact is ejecting 45 Auto dummy rounds, and failures to feed. The most recent nightmare persuaded me to check out my mags.

Any bullets dribbling from your barrel?

Quoted: The springs do extend 2" past the bottom of the mags.

Just go shoot them and see if you have any problems.  I also bought a bunch of G18 33rnd mags and haven't had any problems with them.

double tap.

Quoted: Quoted: Are they factory Glock mags ? Heck yeah, I bought them from MidwayUSA. They have the Glock 7151 +2 bottoms as well.

My guess is your problem lies with +2 bottoms and standard springs. Get some Wolf extra power springs.

Quoted: Quoted: Quoted: Are they factory Glock mags ? Heck yeah, I bought them from MidwayUSA. They have the Glock 7151 +2 bottoms as well. My guess is your problem lies with +2 bottoms and standard springs. Get some Wolf extra power springs.

That is what I am thinking as well. Note that they came out of the wrapper with the 7156 insert and 7151 +2 plate. I figured it was a Glock so I should keep it stock.