Try a new, factory magazine. If the lips of the mag get off the round can release too quick when hit from the rear in loading and cause a similar situation to the description.

 

Who is loading her ammo?

Yes factory hardball, with stock gun components will fix the "problem".

 

Me. Yeah, I know, but she gets what I shoot and it is fine in my Other Brand Guns. The last malfunction I had was with a factory load.

Factory is always the default.

Good idea, I splayed the lips of a couple of metal magazines by dropping them on a hard floor with rounds still in them... USPSA Speed Loads. A friend just got a new Glock, I will have her borrow a fresh magazine to try.

 

A Glock repair tech once told me (calling as an armorer) that if a magazine's steel liner was wider at the lips than normal specification, as the result of either damage or a manufacturing error, it could cause live-round 'stovepiping'. He said the correction was to replace the magazine.

It's easy as a first step to set aside a particular, perhaps questionable, questionable magazine and try another one that's proven its reliability.

FWIW, in my particular case, it turned out that replacing the relatively short-lived #7 .40 followers in a couple of new G27 magazines, with #8 followers Glock sent me, caused my 'problem' to resolve itself.

 

Sorry, I misinterpreted OP-- I was picturing extraction issue (stovepipe) where the empty case is sticking up in the ejection port.

 

It's from not holding the Glock correctly. If the web of your hand is not high in the frame, it will stovepipe intermittently. Mixing bullet weights and springs won't tell you anything without knowing the power floor. Chrono the ammo she currently has problems with. Then chrono factory ammo. I've run some of my mags to over 200K without issues (replacement of springs every 30K or so), and that includes mostly dropping them in USPSA because you never want to go to slidelock. Never had issues with the lips, like CZ's.


Hold your Glock like this.

 

It 'could' be weak RSA, mag springs, dirty pistol

 

Note - it appears most are reading “stovepipe” and not catching its on the load not ejections.

Adding what you did about drop damage, I’m more convinced it’s the mag lips.

 

I suppose I probably should've mentioned that in my case, I was immediately getting live-round nose-up feeding stoppages (called live-round 'stovepipes' by some) with some brand new G27 9rd mags. I discovered the issue when I took them to the range to function-check them with live-fire before carrying them.

Since they were brand new, that's probably why the Glock tech with whom I spoke discussed the possibility of having received new mags with slightly out-of-spec (too wide) liner lips. He was willing to send me the new #8 followers if I wished, but told me if the followers didn't correct the problem, they'd replace the mags.

 

Increase the propellant charge or get a lower power recoil spring. Soft loads coupled with less than firm hold can cause that. This is assuming the the magazines are in good shape.

 

Don't know that a new gun would have feed lip issues or mag spring issues or RSA issues. The other thing is you can use a 40S&W mag with 9mm and it will feed.

 

Not consistently - some will some won’t.

My last two advanced armorer course instructors really beat on mags and the lip specs. They said lot more failures, especially occasional/inconsistent issues are mag related than people realize.