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yosturm

STI 2011 magazine feeding issue

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One of my four STI mags consistently fails to feed in the manner as seen in the photo.  This magazine does so about every 4 rounds.  The magazine has stock STI internals, as do all of my other magazines which function fine.

 

I have the Dawson Precision mag adjustment kit and have "tuned" this magazine as per the instructions on the video.  The critical dimensions of this magazine are within the acceptable specs.  I measure about 1.352 at the back of the lips to 1.360 at the front.  My three other magazines which all feed fine have varying dimensions, some a little bigger, some a little smaller, so I can't figure out why this one magazine is having issues and none of the others.

 

All other surfaces look normal when compared to the other magazines.  Any suggestions?

IMG_00431.jpg

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You have to put grams springs and followers in them.

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But the other three work just fine?  I will swap springs/followers around to ensure that it is this magazine tube and not some combination of springs/followers.

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Do all mags sit at the same height when inserted?

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I agree go with grams guts. Test the bad guts in another mag

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Taran guts work well also.  Is this mag your most used mag?  Is the case not getting underneath the extractor?  Take the spring and follower out of a working mag and test.  The spring could be weak if its your most used mag.  

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I would check your extractor for the following: 1) tension should be just enough to hold the round in place on the breech face (check this with the slide removed from the frame and the barrel removed from the slide), 2) the extractor hook should not be touching anywhere in the beveled portion of the case (the only be contact from recess cut on the extractor and the case rim), and 3) the flat where the case rim rides up on the extractor should be bevelled on the bottom.  

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Thanks for the replies.

 

I checked and it does not sit any higher then the rest of the magazines which function fine.

 

I have swapped the internals with another one and will have to have another range day soon to test that theory.  Magazines are all relatively new.

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22 hours ago, ltdmstr said:

I would check your extractor for the following: 1) tension should be just enough to hold the round in place on the breech face (check this with the slide removed from the frame and the barrel removed from the slide), 2) the extractor hook should not be touching anywhere in the beveled portion of the case (the only be contact from recess cut on the extractor and the case rim), and 3) the flat where the case rim rides up on the extractor should be bevelled on the bottom.  

 

Here's your problem. Your extractor is not allowing the loaded round to come up underneath. I solved it by installing an Aftec.

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With no prior information, I would look at this photo and suspect your extractor as well. With either dummy rounds that are the same length as your match ammo or your match ammo with a shortened firing pin, I would insert each mag and and hand cycle some rounds through your gun.  If they feel chunky, then I would recommend tuning your extractor.  If they all feel smooth, then I would try changing out the springs and/or followers as others have mentioned.

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7 hours ago, MikieM said:

 

Here's your problem. Your extractor is not allowing the loaded round to come up underneath. I solved it by installing an Aftec.

 

But could that be the case if all of the other magazines have 0 malfunctions and only this one does?

 

Either way, I will hit the range this weekend and test the swapped magazine internals to see how that works.

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Posted (edited)
52 minutes ago, yosturm said:

 

But could that be the case if all of the other magazines have 0 malfunctions and only this one does?

 

Either way, I will hit the range this weekend and test the swapped magazine internals to see how that works.

 

What I said isn't etched in stone. The change in extractors worked for me.

If that one mag is the only one with malfunctions then I would certainly look at it first. Check the dimensions. Adam, at Atlas Gun Works, has some good videos on YouTube about tuning magazines.

Load ten, or more, rounds into the mag. With the magazine in the gun note that the first round should (ideally) be pointed at the center of the chamber. The first round should (again ideally) be sitting flat against the second round in the mag. This will occur when the mag feed lips are set correctly.

Check the dimensions of the bad mag against the good ones. Take the spring out and make sure the bottom of the follower is not cocked one way or the other, and that there are no twists in the spring. A weak spring usually causes nose dives, and a twisted spring will act like a weak spring.

When everything is back to where it should be, load the magazine fully and let it stand in a dark corner for a few days. New mag springs are like ex-wives. They have good memories.

Good luck.  :D

Edited by MikieM

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22 hours ago, MikieM said:

 

Here's your problem. Your extractor is not allowing the loaded round to come up underneath. I solved it by installing an Aftec.

 

Aftec is a good choice.  But they are not a drop in part.  They still need to be checked and tuned for the same three things I listed.

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49 minutes ago, ltdmstr said:

 

Aftec is a good choice.  But they are not a drop in part.  They still need to be checked and tuned for the same three things I listed.

 

You're absolutely right.

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Internals swapped and about 100 rounds later, No more of the first malfunction (as described in initial post) but I did get one of these (see photo).  This second malfunction occurred with a different magazine.

 

Then another range session later, about 120 rounds, and I have two of malfunction #2, one of the original malfunction, and one stovepipe.

 

I don't recall exactly which mags had which malfunction, but it felt like it wasn't a specific magazine that was causing all of the issues.  From the previous posts/discussions I understand how the initial malfunction could be magazine related. But I feel like this new malfunction might be something with the slide/recoil spring.  I have the stock recoil spring, Pistol has about 1000 rounds through it.  I do have an aluminum shok-buff and wonder if this could be playing a part in these malfunctions.  Next time I am at the range I will take it off.  Any other thoughts?

 

 

IMG_0065[5205].JPG

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Empty brass still in gun is often a sign of a short stoke.  Really light loads?  Full strength recoil springs are usually pretty stout.  If the loads are really light, slide isnt making full travel which could be causing both of your issues.  Possibly.  It could also be the shock buff which is between guide rod head & spring so causing the spring to have to compress even shorter to get full stroke which could be adding to the issues

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Start by ditching the shock buff and grab a tuning pack of recoil springs

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So I took my slide off and tested the extractor with the "feed a round into it and see if it jiggles" test.  Definitely the extractor.  I ordered an Aftec, so I will throw that in and run to the range once it arrives.

 

 

 

 

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Don't just throw it in, needs to be fitted properly, which is not necessarily making sure the fp stop is fit correctly, like ltdmstr said above.

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On ‎4‎/‎18‎/‎2017 at 7:53 AM, Glk21C said:

Don't just throw it in, needs to be fitted properly, which is not necessarily making sure the fp stop is fit correctly, like ltdmstr said above.

 

Yep.  Good thing I decided to give the old fashioned bend it a little and throw it back in a try.  Because I am still new to the 2011 game so for some reason I was expecting the Aftec to be drop in.  Once it arrived it was clear to me that it wasn't (didn't even fit my firing pin stop).  This will require no small effort of fitting to work.

 

I ended up retuning my existing extractor and throwing that back in since I had a match last weekend. 

 

Now the decision is, do I keep the Aftec, buy a second firing pin stop, and attempt to fit it?  Or do I just return the Aftec and stick with the stock ejector?

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Also, since I don't know where else to put this, my stock extractor does not come out easily.  I have seen plenty of videos on the internet where the gunsmith pops it out quite easily and the extractor just slides out after a little caressing up front.

 

Not only does mine seem to need a lot of pressure to get it past the breech face, but once that has been accomplished it is still hard to remove and does not just fall out.  I have to use a tool to pull it out the back until about half way then it comes out easily.

 

Not sure if this is normal or another indication of poor setup.

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I would still take out the shock buff and try it.
The extractor in my infinity is the same way to remove. It's not an aftec.


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Lighter recoil spring looks like it's necessary.


Sent from my iPhone using Tapatalk

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