Glock Mag TUBE failure

[mstamper]

I recently had a Glock 33rnd mag fail on me. It was attached to a TF 41+1 extension using their spring.

The mag would load ok, but feeding was the problem. It would feed 3 or 4 rounds and the follower would not advance. I would have bump the mag to make it work. After stripping off another 3 to 4 rounds it would happen again. 

This mag had been working fine for over 800 rounds.

 

thinking this was an issue with a dirty mag I took it apart and cleaned the tube, spring, follower, and pad. reassembled it and the same issue was still there.

I inspected the spring and it was twisted more than 15 degrees. I reached out to Robin at TF and we diagnosed the issue and felt it was a bad spring. He sent me a new spring. I installed the new spring and the issue was still there.

I compared the new spring against the old one. The old spring was several inches shorter and obviously twisted. To diagnose it more, I took my other 33rnd apart and put the old spring in that tube. The mag fed but you could tell that the spring tension was not right. I put the new spring in my 2nd 33 rnd tube with the TF pad and it loaded fine and stripped off rounds properly. I also put the 33rnd spring into the old tube and the feed problem remained.

 

This brings me to my question; can a magazine tube become torqued enough to cause the follower to jam in the tube? Looking at both, I do not see any twist but the tube will not allow the rounds to advance properly.  I am very confused about this. I am ordering a couple of new OEM 33rnd mags from shooters connection.

 

If this is a common thing, shouldn't the tube have lasted more than 800 rounds?

[HoMiE]

Did you watch the TF video on how to modify the follower?

[mstamper]

5 minutes ago, HoMiE said:

Did you watch the TF video on how to modify the follower?

yup, did EVERYTHING suggested. Did all that when I assembled the pad onto the tube

 

[HoMiE]

What OAL are you loading to? I had some issues loading past 1.145”, the bullets start to tip down as you load and then would stick. I shortened up my load to 1.125” and so far so good. 

[mstamper]

5 hours ago, HoMiE said:

What OAL are you loading to? I had some issues loading past 1.145”, the bullets start to tip down as you load and then would stick. I shortened up my load to 1.125” and so far so good. 

I am loading to 1.13 to 1.135

Like I said I have run over 800 rounds. 500 were factory ammo that was longer OAL with NO issues at all.

[Aircooled6racer]

Mark: Put the mag together with all the stock parts and see if it works perfectly. If so then it is a spring, follower and base pad problem. It could be the transition between the base pad and tube. Look for loose pieces of plastic in the tube. This is for factory Glock magazines. Thanks, Eric

[mstamper]

44 minutes ago, Aircooled6racer said:

Mark: Put the mag together with all the stock parts and see if it works perfectly. If so then it is a spring, follower and base pad problem. It could be the transition between the base pad and tube. Look for loose pieces of plastic in the tube. This is for factory Glock magazines. Thanks, Eric

I did do that and the old tube still would not feed properly

[HoMiE]

Maybe the mag body got too wide and there is a section where the bullets are able to roll over just a bit too much. Do you use one of those loaders to load up mags? 

[JAFO]

I have heard of Glock tubes bulging when left fully loaded for extended periods, but that was on handgun mags and the main problem seemed to be not falling free of the magwell.  You could lay the sides of the tube on a level and see if it looks bulged or deformed anywhere.

 

You mentioned swapping springs.  Have you tried swapping followers?

[mstamper]

I have heard of Glock tubes bulging when left fully loaded for extended periods, but that was on handgun mags and the main problem seemed to be not falling free of the magwell.  You could lay the sides of the tube on a level and see if it looks bulged or deformed anywhere.
 
You mentioned swapping springs.  Have you tried swapping followers?

I also swapped followers.
I am pretty sure every iteration combination to figure this out

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[mstamper]

1 hour ago, HoMiE said:

Maybe the mag body got too wide and there is a section where the bullets are able to roll over just a bit too much. Do you use one of those loaders to load up mags? 

not sure what sort of loader you are talking about but I use a Uplula loader on all my magzaines

 

[HoMiE]

36 minutes ago, mstamper said:

not sure what sort of loader you are talking about but I use a Uplula loader on all my magzaines

 

That may be compressing too much and making mag body swell or bulge too much. Are you using uplila to stuff 41 into mag? I load by hand and it’s pretty tight to get that last round in. Most of the time I just load to 40 since it’s easier to seat mag. 

[Aircooled6racer]

Mark: I would look inside the magazine and see if there is any loose plastic in there. You could also measure the mag along the sides to see if you have any area that is alot wider than the rest. I don't think that will be the problem since I have some 33rd Glock factory mags that are over 10 years old and they still are going strong with the same spring and follower. Thanks, Eric

[mstamper]

9 minutes ago, Aircooled6racer said:

Mark: I would look inside the magazine and see if there is any loose plastic in there. You could also measure the mag along the sides to see if you have any area that is alot wider than the rest. I don't think that will be the problem since I have some 33rd Glock factory mags that are over 10 years old and they still are going strong with the same spring and follower. Thanks, Eric

I will. I will bring the tube with me Saturday to RBGC and let you take a look at it. This is more of an academic discussion as I have replacement mags on the way. I was just really surprised that a relatively new magazine failed so early. I thoroughly cleaned the mag, looked for any debris or shaved metal or plastic, tried an unmodified follower, factory 33rnd spring and OEM pad, old spring and unmodified follower, new spring and old follower, new extended spring and both new and old follower. Every possible combination I could think to try. The end result was that any spring and any follower with the TF pad or the OEM +2 pad resulted in failure to feed the rounds up the tube. 

 

I put the new spring with the TF pad onto the other 33rnd mag tube and it worked fine. 100% feed with great tension on the rising bullets up the tube. Just weird, just plain weird.

 

[Aircooled6racer]

MarK; I will have a look at it for you. I have some spare mags you can borrow if you need some? Thanks, Eric

[mstamper]

1 minute ago, Aircooled6racer said:

MarK; I will have a look at it for you. I have some spare mags you can borrow if you need some? Thanks, Eric

Thanks Eric,

My new mags should be here before the match Saturday. If not, I will take you up on your offer.

[ToddKS]

I know this is acedemic now but has the mag ever been dropped? I sounds like the bottom of the tube could be slightly tweaked.

[mstamper]

3 hours ago, ToddKS said:

I know this is acedemic now but has the mag ever been dropped? I sounds like the bottom of the tube could be slightly tweaked.

it has been dropped during mag changes. I guess that could do some tweaking. with as many people I know who use these mags and the TF base pads I would have thought there would have been other reports of this same sort of issue.

[Aircooled6racer]

Hello: I looked at the mag today and it has a metal piece sticking down in the mag where the two pieces join together like interlaced fingers. It was about 3/4" from the top. Looks like it would catch on the case to me. A little smoothing out should fix it. Thanks, Eric

[mstamper]

11 hours ago, Aircooled6racer said:

Hello: I looked at the mag today and it has a metal piece sticking down in the mag where the two pieces join together like interlaced fingers. It was about 3/4" from the top. Looks like it would catch on the case to me. A little smoothing out should fix it. Thanks, Eric

Thanks again for taking a look at the tube for me. I had looked at the insides of that maybe a dozen or more times and never saw that burr. That is why it is good to get another set of eyes on it. 

[mstamper]

Reviving this thread.....

the reason for that is for an update on the original issue and to report about the same issue arising again with a different glock mag.

 

After looking at the mag and replacing the spring provided by Robin Taylor over at Taylor Freelance and the replacement spring NOT fixing the feed issue with that glock tube. I ordered a new mag and put the new spring in that new tube. That magazine has been working fine. 

 

I had the same issue arise with my other 33rnd mag with a TF extension and the extended spring that Robin sells this past weekend. The mag failed after 3 shots in a stage. When I pulled the charge handle I saw several rounds loose in the front of the BCG. I had to drop the mag and had my Oh s#!t mag with me and was able to finish the stage with 2 rounds to spare. I noticed that prior to the start of that stage, when I was reloading the mag, the spring felt "spongy". 

 

I changed out the spring with a spare extension spring I had into the same tube today and just like in the first post, the new spring would not feed properly in the tube that had the feed problem. Somehow the spring fatigue does something to the tube as well. (my guess is the heating and cooling of the mag from over 6 to 7k rounds torqued the tube just enough to not allow it to feed properly). I had a spare 33rd mag and put the new extension spring plus the TF extension on it and it runs fine. 

 

I am really at a loss as to why this is happening. This is twice. both mags are around 5 months old. I have done some research on the web and cannot find where anyone is reporting this issue. I did some math. Over the 5 month period, I have shot about 11 stages a week with an average stage count of 220 stage. Multiply that by 40 rounds per mag, that is over 8k round in and out of the mags and about 5500 to 6500 rounds shot.

 

I do unload my mags after each match. I have ha some people tell me that not keeping them loaded causes early fatigue of the spring. Is that actually something that is documented? 

 

Do Glock mags not hold up to that level of use?

Is this something unique to my PCC? 

Poor workmanship in the mag production?

Poor workmanship with the spring manufacturer. (Wolff)?

does my loading and unloading the mags cause the spring to fail prematurely? 

 

 

I am open to hear the thoughts from my fellow PCC shooters using glock mags.

Edited August 28, 2018 by mstamper

[CalTeacher]

I had this issue and it ended up being an ammo problem.  Simple as that.  Salt shaker mags that previously worked, both Glock and ETS.  I now load to 1.135 with one type of bullet.  Make sure you're not overcrimping (I was crimping to .372", now I'm at .378") and bulging the case below the mouth as it will impact feeding in big sticks with extended base pads.  These mags are finicky because of the tapered 9mm case.  Your ammo needs to be on point for these mags to function properly.   

[JZELEK]

Recommends OAL of 9mm rounds to be 1.125

[gerritm]

I have looked, but don't see it in your posts.  Are you beveling the inside edge of the Glock mag slightly right at the transition from extension to mag to allow the follower to smoothly move into the mag from the extension. I bevel all my Glock mags with the big extensions/long springs from TF & MBX . I have had this same issue as you when I got in a hurry and didn't do this to a new mag & extension. I run TF extensions for 41 rounds & MBX to 57 rounds full. I do usually download 1 or 2. I do not modify the followers. We run 2 different PCC's & Shoot thousands of rounds a year with no failures. 1.12 OAL RN Everglades Plated. I do have the Taccom feed ramp. Best $20 I have spent.

 

 

gerritm

[mstamper]

I have looked, but don't see it in your posts.  Are you beveling the inside edge of the Glock mag slightly right at the transition from extension to mag to allow the follower to smoothly move into the mag from the extension. I bevel all my Glock mags with the big extensions/long springs from TF & MBX . I have had this same issue as you when I got in a hurry and didn't do this to a new mag & extension. I run TF extensions for 41 rounds & MBX to 57 rounds full. I do usually download 1 or 2. I do not modify the followers. We run 2 different PCC's & Shoot thousands of rounds a year with no failures. 1.12 OAL RN Everglades Plated. I do have the Taccom feed ramp. Best $20 I have spent.
 
 
gerritm

Yes. I've done everything you are supposed to do. My oal is 1.125 as well. The mags function flawlessly for a while then the above issues start happening

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