I have a student with a Glock Gen 5 9mm. He has fired about 200 rounds with it and it works fine for him while shooting. While doing malfunction drills with it about 50% of the time the slide will not unlock to eject a round. By pulling and pushing on the slide a few times I can get it to unlock and operate. This only occurs when there is a loaded magazine in the pistol and the trigger has been pulled. It feels like something is binding but then lets go. What gives? Could it just be my dummy rounds?

Don't know about your dummy rounds, but I've had the same problem with some of mine. Primarily the solid plastic type. Don't recall if it happens with the premium spring-loaded.

Hard to eyeball in advance, but the round usually looks a little rough and/or beat up in the base/rim area. Never bothered to examine the specifics of why. I just chuck the dummy round in the trash and replace it.

I believe the best dummy rounds available are the S.T. Action Pro. They use real cases with solid plastic inserts. They are extremely durable and last a long time before becoming so battered as to be unreliable.

https://smile.amazon.com/s/ref...eywords=dummy+rounds

(Note that they are not snap caps. The primer cups are hollowed out.)

Sounds very much ammunition-related to me. Try some snap-caps, something with a brass base to grab, rather than plastic.

quote:

Originally posted by sigfreund:
I believe the best dummy rounds available are the S.T. Action Pro. They use real cases with solid plastic inserts. They are extremely durable and last a long time before becoming so battered as to be unreliable.

https://smile.amazon.com/s/ref...eywords=dummy+rounds

(Note that they are not snap caps. The primer cups are hollowed out.)

Yes those are what I am using but they have had a lot of use. I am just puzzled why it is only a problem in the Gen 5 Glock. Perhaps the tolerances are tighter in the Gen 5. Thanks you all for your thoughts.