[Kramer]

I just picked up a new Glock 20 Gen 4 and 9 out of 10 times the slide will not go back on the gun unless the trigger is moved to the firing position. I stripped the gun and cleaned out firing safety hole since I have read this can be the culprit. No dice. I had a very difficult time getting the ejector plunger back in and could only do so when i farted around with the firing pin safety.

The gun can only be assembled if I have the trigger in the firing position or if I press the firing pin safety in manually and let the firing pin move all the way forward. Otherwise the gun fires fine.

I've searched a few posts and some say this is normal for late Gen 4 and late Gen 3 Glocks but I have never had this happen and cannot recreate this condition an any of my other Glocks regardless of the generation. Any thoughts?

 

[kimberguy2004]

The terminology in this post makes it really hard to understand the problem. But...
The first step is insuring the firing pin safety is installed correctly, When you look at the side of the slide you should have the metal part of the extractor plunger against the extractor. You should also be able to manually depress the firing pin safety and hear the firing pin rattle when you shake the slide. The firing pin also has to be in the forward position when you put the slide back on. If it isn't depress the FP safety to release the FP.
If you have taken the trigger components out, check that the trigger spring is correctly oriented. It can be reversed and that will cause problems. I'm not sure if it will prevent replacing the slide on the frame because I have never reversed it, but something is not put together correctly/