G42 oddity.

[CZ9shooter]

Many of us have heard about the reported problems with the slide failing to lock back. I get it. Some parts have been updated since then, or the ammo was underpowered, or the slide release is being contacted during recoil. I do not believe that to be the case here.

I have all the latest parts. My 42 is only a couple months old. I have tried factory ammo and reloads, from medium to full throttle. Mine are 100gr Berry's ranging from 800 up to 950 fps.

In every case I get a failure of the slide to lock back... with me shooting it anyhow. I am not touching the lever. I have been paying very close attention to it. However, It works like it should 90%+ of the time when my wife shoots it. Also, if I intentionally limp wrist it on the last round it locks back reliably. What gives? Glocks like loose wrists now!?

It's mostly her gun, so I am not too concerned over the whole thing, but it has me wondering. Seems backwards to me.

 

[kokapelli]

I have two G42s and both are perfect, so it's not normal.

 

[azrocks]

The most likely cause is that you're contacting the slide lock. I know you said you're not, but...

Is it at all possible that in your attempt to limp-wrist the gun what you're really doing is changing your grip just enough not to contact the slide lock (where you were before)?

How do you know you're not contacting it?

 

[MikeJackmin]

Have you tried another magazine?

 

[CZ9shooter]

How do you know you're not contacting it?

I understand what you mean. All I can say is that I am shooting it with my thumbs stretched out as far away from the gun as I can get them. I guess I cannot say with absolute total 100% certainty that I do not touch it because things happen awfully fast during recoil, but I am pretty sure.

Have you tried another magazine?

I've got two Glock mags. No difference.

 

[MikeJackmin]

OK I'm just guessing here.

There's several parts that work together to make the slide lock back. Perhaps this system is only working marginally with your pistol, with the (presumably) softer grip of your wife's hand being enough to tip it from non-functional to mostly-functional.

Things to consider include the stiffness of the magazine spring, the magazine follower, the slide lock lever and spring, and the notch in the slide itself.

The magazine spring is the usual culprit, but if both of your mags are doing this, and if factory mags tend to not have this problem, then that seems unlikely. Hopefully the mag is clean and the follower is moving smoothly. The contact between the slide lock lever and the follower might not be square - perhaps you can see a wear pattern where these two parts contact each other to assess this.

If a softer grip makes it better, that suggests the slide is moving too fast when a firmer grip is used. Maybe a stiffer recoil spring would fix it.

I think there is a spring that lifts the slide lock lever, which helps reduce the bounce back which otherwise might occur. Replacing that spring might help too.

A stiffer mag spring can't hurt either. The current weight of the mag spring might not be causing the problem, but a stiffer spring might help overcome it.

There's not much you can do about the notch in the slide. I suppose a replacement slide lock lever would be the last-ditch attempt.

 

[CZ9shooter]

Good points. Especially about slide velocity. Maybe some more experimenting is in order. Thanks.