Glock 20 ejecting magazines

[Muskrat]

So my Glock 20 has started kicking the magazines out during fire. I have one magazine that the gun has rejected in the past, but now it's ejecting all of them, now and again.

No real rhyme or reason to it...about the only constant is that it almost always kicks the mag out on the last round, accompanied by a stove pipe.

I've swapped out recoil springs...stock Gen4 spring, 22lb spring, 24lb spring. Doesn't seem to affect it.

I GUARANTEE that my finger...any finger...isn't hitting the mag release button under recoil.

So I ordered a new magazine catch and associated spring, but both of those parts look factory-new, so I'm leery.

It's happening with a variety of loads...loads I've been shooting for a long time, and all of my magazines. I can't think of anything that's changed about the gun, but of course things wear.

Anyone have any insight on this problem?

Thanks!

[tommac919]

Sounds like a weak spring for the magazine catch or the catch itself

So did you change them out ? ( vids on the internet if unsure how )

[The_Shadow]

Muskrat have you inspected the slots on the magazines for issues?  I would assume that you give them a firm tap to fully seat them up on to the mag catch.
Good luck getting it fixed up!

[Muskrat]

The magazine catches show slight deformation, but no more than usual for Glock mags. The newest mag actually pops out the most frequently...has since I bought it, so I retired it to the Banshee. Magazines are fully inserted, and have stock mag springs.

The local shop didn't have the parts I needed (catch and spring) so they're on order, and maybe that's the fix. I'm still puzzled though...I have other Glocks with ten-times the round count that have never needed any part replacement. Why it would all of a sudden start popping mags is something I can't put my finger on. Obviously it's recoil related, but the mag-catch really shouldn't be moving under recoil.

I've read about trimming the plastic at the top of the mags to keep the slide from impacting it on recoil, but I can't make heads or tails of what they're getting at.

[The_Shadow]

That is unusual for sure!

[Graybeard]

The magazine catches show slight deformation, but no more than usual for Glock mags. The newest mag actually pops out the most frequently...has since I bought it, so I retired it to the Banshee. Magazines are fully inserted, and have stock mag springs.

The local shop didn't have the parts I needed (catch and spring) so they're on order, and maybe that's the fix. I'm still puzzled though...I have other Glocks with ten-times the round count that have never needed any part replacement. Why it would all of a sudden start popping mags is something I can't put my finger on. Obviously it's recoil related, but the mag-catch really shouldn't be moving under recoil.

I've read about trimming the plastic at the top of the mags to keep the slide from impacting it on recoil, but I can't make heads or tails of what they're getting at.

I've read that some Glock mags are being impacted by the slide and can be trimmed, too. What I've seen suggested is remove you recoil spring and insert an empty mag. Press the bottom of the mag firmly against a table and slowly cycle the slide. Try to feel if the slide is hitting the notch in the back of the mag. If it does, file a little material off until it doesn't.

Lots of posts on other forums about this. Seems like it's not just G20s. Good luck with this. I hope you figure it out.

[Muskrat]

So the culprit seems to be a very slight deformation in the magazine catch where it engages the magazine. It was not perceptible until the catch was removed and examined next to a new catch under a magnifying glass. I replaced the spring while I was at it, though I doubt it was necessary.

Since I use the Brooks Tactical A-Grip, removing the magazine catch costs me $30 in a new grip...bummer. But I do love that grip!

I still have some questions as to why there's enough force on the catch to deform it, as it's never happened to any of my other Glocks, but I've yet to find any plausible reason other than the increased recoil of the 10mm cartridge.

[Keiichi]

It could just be a manufacturing defect. Metal that isn't properly hardened would deform with use, I've seen it in components in other pistols. Sometimes you end up with a lemon.

[rognp]

Knocking the dust off this one, I just have to wonder, could there be some debis or other form of foreign material interferimng with the function of the latch assembly. Coul explain the mysterious appearance of the malfunction.

[jazzsax8]

I read something about firming up the magazine in the well by putting some aluminum tape on one side of the magazine to help reliability.  I did it even though had not experienced that problem.   If you could have a problem like yours on the last round only, it could be considered a positive!  Automatic ejection needing the next mag.

[jmm701]

I had the same issue with every magazine that came with my G29.  I put some duct tape on the side of the magazine that the magazine release button is on and that fixed it.  So if you have it on the left like it came from the factory then try putting tape on the left side of the magazine with the round count numbers facing you and vice versa.  You will have to experiment with the thickness to get it right.