Glock Mag Tube Lifespan

[bulldog009]

Over the last 5 years of shooting primarily PCC, I've noticed that Glock mag tubes have a lifespan limit. After roughly 4k-5k rounds, I have to change the mag tube that's wearing my mag extension. I'll start getting FTFs caused by the mag lips wearing out and presenting the round at a higher angle, then the bolt slams the round into the face of the barrel above the chamber. Does anyone else have similar issues?

If so, how are you dealing with it - just replacing your mag tube after X number of rounds, using a barrel with feed ramps, running a MBX steel mag? 

My build for reference - Spikes lower, Aero upper, JP buffer (not short stroked), JP bolt, JP 16" barrel. 

[CClassForLife]

Good to know, I haven't shot enough rounds to encounter this yet.

 

I would just replace the mag tube since you can get 4+ of them for the price of one MBX mag.

[egd5]

I have several mags and have a bunch of rounds through them- I'd guess way more than 4-5K. Mine all work fine. I'm using a JP gmr-15 fwiw.

Sounds like more of a follower or spring problem to me.

Edited February 23, 2022 by egd5

[ChuckS]

I have lost only one mag in the last 5 years (~35K lightweight  ) and that was due to the weld up the back of the tube splitting and causing drag on the aft end of the follower. About 27K of that was with a non-ramped barrel. For the record: NFA lower, Alpha Sports un-ramped barrel, short stroked uppers. Stock tubes with Grams springs and followers.

 

[Faith02]

I haven't experience this before, maybe i haven't shoot enough round yet .

[dtsdave]

To the OP, Are you leaving your mags loaded to capacity in between matches?  I can imagine that without bullets in the mag there would be a lot less pressure on the feed lips during storage.  

[bulldog009]

On 2/23/2022 at 1:23 PM, egd5 said:

I have several mags and have a bunch of rounds through them- I'd guess way more than 4-5K. Mine all work fine. I'm using a JP gmr-15 fwiw.

Sounds like more of a follower or spring problem to me.

 

I've never changed out the spring or follower because it always looks like a feed lip issue. You can see a noticeable difference in the angle of the top round of the magazine, I'll try to get a picture of it if I still have one of those tubes laying around. 
 

On 2/23/2022 at 1:28 PM, ChuckS said:

I have lost only one mag in the last 5 years (~35K lightweight  ) and that was due to the weld up the back of the tube splitting and causing drag on the aft end of the follower. About 27K of that was with a non-ramped barrel. For the record: NFA lower, Alpha Sports un-ramped barrel, short stroked uppers. Stock tubes with Grams springs and followers.

 

Wow, I wish I could get that round count out of a single tube. This has not been an isolated occurrence for me either, I've had to replace at least 4 tubes that I can think of, and they've all had this same issue. All of them were gen 3-4 tubes (non orange follower) if that has anything to do with it, I'm not sure. My current tube is a gen 5 tube with the orange follower, it will be interesting to see if that makes any difference. 
 

3 hours ago, dtsdave said:

To the OP, Are you leaving your mags loaded to capacity in between matches?  I can imagine that without bullets in the mag there would be a lot less pressure on the feed lips during storage.  

No, the only mag that stays loaded is my home defense gun. All other mags are unloaded after a range trip. 

Edited February 25, 2022 by bulldog009

[Yeti]

The weight of all those rounds come to bear on the feedlips during aggressive slide lock reloads.  The ammo stack will bounce slightly and hammer the feedlips apart over time.  Could that be a factor?

 

[bulldog009]

2 minutes ago, Yeti said:

The weight of all those rounds come to bear on the feedlips during aggressive slide lock reloads.  The ammo stack will bounce slightly and hammer the feedlips apart over time.  Could that be a factor?

 

Potentially, yes.

The more I think about it, and gather info and other people's experiences, I am beginning to wonder if it may have something to do with my particular lower. Spikes is not a name you see a lot in PCC circles, it just happened to be one of the ones available when I built this rifle several years back. Maybe it seats the mags a little too high and that's causing the bolt to make more contact with the magazine than with a different lower. I'm the only one running a Spikes lower in my area, and I don't know of anyone else having these mag issues that I shoot with regularly, so maybe its the lower. 

[egd5]

Are there any wear patterns on the bottom of your bolt (or the mag) that might indicate the bolt striking the mag ever so slightly?

Can you get with a friend who has a different brand lower and compare the two side by side to see any difference?

[Yeti]

Curious to hear about what you may find in direct comparisons.  Please keep us posted.