I went to the range yesterday with my Gen 3 Glock 17, I used four Gen 4 Magazines. Occasionally with rounds in the magazine it would go to slide lock. I would release the slide by using the slide stop (Vickers Tactical).
Today I went back to the range with my Gen 4 and Gen 3 mags, I experienced the same issue with the Gen 4 mags. I didn’t have any issues while using the Gen3 three mags.
Do you know if anyone else has had this problem with the Gen 4 mags or a possible remedy?
Thanks,
Jason
I just don’t see how a bullet could hit the slide stop so I’m gonna blame your thumb.
I thought the same thing while at the range, It’s not the thumb.
And only happens with Gen 4 Mags not Gen 3 mags.
Pretty much all my mags are gen 4 and I don’t have the problem unless my thumb gets in the way. That is also why I don’t run extended controls anymore.
The slide top being extended isn’t an issue. I’ve not had a problem until I bought the Gen 4 mags. There still a lot of people who still have the gen 3 mags.
Did you install the slide stop properly? Is the spring underneath the locking block pin?
What followers do your generation 3 magazines have? This shouldnt matter as i am 99% sure this is user induced but we should ask anyway.
The slide stop was installed properly. If it wasn’t the slide would lock no matter which mags I was using. Gen 3 mags have #6 and #5 followers the Gen $ mags have #6 followers.
That is not true. With no spring tension, the slide will lock back intermittently during firing which is why i asked.
That’s exactly what I said it would lock no matter what if it was installed incorrectly.
I’ve seen then incorrectly installed before which caused the slide to lock open which I have fixed on several others pistols.
You’re obviously not following my logic train.
With no spring tension, the most common issue is intermittent slide lock.
With no spring tension, the slide MAY or MAY NOT lock back upon empty.
Dimensionally, the generation 3 and 4 magazines are the same minus the right hand (or left hand shooter) relief cut for the magazine release. The follower should be at the same height between both magazines so the difference between 3 and 4 may be purely circumstantial. Do you have your magazine release reversed for left handed release? IF there was a difference in height of the follower there would be a possibility that manufacturing variation has the tab on the slide release too low but again, this could only occur if the tab was contacting your follower.
Is this happening with the factory release?
Not to be argumentative I’m following logic and I have a Gen 3 Glock 17 which is impossible to change the mag release to accommodate a left handed shooter. To make it simple the slide stop is and was installed properly and my support thumb and hand placement is not an issue.
Have you tried swapping back to the factory slide stop and see if the issue persists?
They must be trash, just mail them to me. 
I’ve beer seen that issue except bumping with hand placement. Are you shooting with both hands when this happens or just one hand?
I had this issue with a new sig scorpion 229 but not the old German 229 and then tried one handed thumb down and problem magically went away. Realized then that the VZ grips were a bad style for thumbs up/forward on the newer 229.
If it is happening with both hands on weapon. Try one handed thumb down almost tucked to completely Tay clear of the slide stop to double check
Probably not since the slide stop has been installed for over a year and I haven’t had any issues since I bought the Gen 4 mags a few months ago. I may experiment a little more next week.
I had the same issue with my G 27. As other suggested I was probably hitting the slide release with my thumb so I started shooting left handed(I am a natural lefty so no big deal) and the problem went away. I would try shooting a couple of the Gen 4 mags left handed and see it that solves the issue. It did for me.
I had always shot my G 22 and others just fine but I guess was just something with my grip with the subcompact. I would at least give lefty that should let you know if it is you or the mags. Hope this helps.
My Gen4 10mm will do this. Almost certainly a thumb issue on my part, but it only happens with one round left in the magazine. At least I’m consistant.
This.
I want to thank everyone who responded as I appreciate your your input.
For those of you who believe the slide locking open with rounds in the mag is caused by my support thumb and or pad of my hand, then why does this only occur with the Gen 4 mag and not the Gen 3 mags?
I ran 250-300 rounds through it and it “ONLY” occurred with the Gen 4 Mags.