On a Glock (high mileage G42) what could cause the gun to cycle but not reset the trigger?

[Quiche]

I have a Glock 42 that I've been shooting pretty heavily for a year now. I have about 2k to 4k rounds through it. Recently it started choking up, mostly the slide locking back when the magazine was not empty (this is with the '03' marked mags that have worked fine for the past year), but occasionally it would cycle and a round would chamber just fine but the trigger would not reset.

I changed the recoil spring assembly (which I've read needs to be done sooner on these smaller guns than on duty size guns) and gave it a good lube and put about 200 rounds though it. It worked a lot better but I still had one time when the gun fired, cycled and ejected the casing just fine and loaded a fresh round but the trigger didn't reset. This happened with steel ammo which is typically less reliable than brass in my 42 but I still can't imagine what malfunction could cycle everything but not reset the trigger. I have a ghost connector and some springs in it but on my next outing I am going to change those back to stock and try to get through another 200 rounds.

Are there other parts of a G42 I need to be changing out every ~4k rounds? Is it possible I am over-shooting this gun? I'll frequently load up magazines and fire 50 rounds over a few minutes before loading them all up and doing it again. Lots of dryfire practice too.

[JohnKSa]

Can't imagine why the case material would have any effect on the trigger reset.I am going to change those back to stock and try to get through another 200 rounds.That is a good approach to troubleshooting. Let's get back to a baseline configuration and then we can work from there. The trigger spring and connector definitely affect trigger reset.

Does the trigger ever fail to reset during dryfire practice?

[Quiche]

No, it never fails to reset during dryfire. Let me mess around with it a bit...

Trying it now I see that the trigger is all the way to the rear when the trigger is not reset. The failure at the range I had I remember the trigger not being to the rear but in pulling it it feeling spongy. I was able to pull it through but it was feeling a lot lighter than normal and and I was not feeling or hearing any clicks (or bangs) when I pulled through. I then came off the trigger and pulled the slide back and a live round ejected. I should have inspected for a primer strike but I just kept shooting thinking the problem may be reoccurring from what I was having before. But that was the only failure I had during my last outing. I also seem to remember the recoil feeling different on the previous shot and I was half expecting a failure when I pulled the trigger.

Dryfiring it now I can get the same experience to the 'failure' I had from intentionally short stroking the trigger. It could just be I wasn't coming off the trigger enough since I was shooting slow for accuracy on paper. Especially since every time I tried to cause a malfunction through mag dumping everything worked fine.

[JohnKSa]

Trigger forward without the trigger bar engaged with the striker should never happen. That means that the striker reset the trigger but then somehow the trigger bar then came out of engagement with the striker. That's a fairly serious malfunction as there is some potential for that kind of malfunction to result in doubling or even full-auto fire.

In a properly operating Glock, there is no way to "short stroke" the trigger.

Try going back to the stock parts and see how it operates.

[Groundhog34]

I had a 43 that had the same issues. I drove over to Atlanta 100 miles Glock replace the firing mechanism and it has been 100% since. They replace the connecter with a 3.5? connector and the trigger is excellent.