G20 Gen4: FTF Issues

[The_Shadow]

The machine purchase where the RSA sits in the gen 4 slide is bigger in diameter that the older generations.

You can see and read about changes here...http://www.udpl.net/glock/20100705G3G4.pdf

[chucky2]

Wow, I stand majorly corrected.  I always though the significant changes where just the RSA and the backstrap for Gen4...there really is a difference looking at that doc.  Does it hold true for G20, that document?

[Geeman]

I'd be willing to ship my slide to someone who has a scale and a Gen3, just to see how close to each other they are.  I'm curious...I can't believe they'd have changed the Gen4 slide to such an extent it wouldn't be very noticable, could they?

Gen4 slide on a postal scale, no barrel, no spring weighs 1 lb  1.2 oz.

Greg

[chucky2]

If I brought by slide into our local fine southern suburb of Chicago postal office to be weighed, they'd probably go postal on me. 

[chucky2]

Anyone close to Chicago area with a working G20 Gen4?

[orangeride]

I had a brand new gen3 20sf with similar problems. Lucky for me I had a box full of spare parts that I started changing out one at a time. Ended up being the ejector. It was out of spec nicking the shell on the way in causing a nose up left side jam. Cheap part. Maybe 10-12 bucks. It might be the pbr has a slightly different shape making things worse. These guns should be very tolerant of different loads. This would explain your empty left in the breach face. Also the gen4 RSA seem to be stiffer than gen 3's. Most of gen3 that have feed RSA problems are with stiffer springs. You might try leaving the gun locked back for few days to lossen it up

[4949shooter]

Failure to extract/eject could be the RSA as mentioned.

I would contact Glock before your warranty gets too far out of expiration. Let them try to figure it out for you. You still may be a candidate for a replacement gun.

[chucky2]

I had a brand new gen3 20sf with similar problems. Lucky for me I had a box full of spare parts that I started changing out one at a time. Ended up being the ejector. It was out of spec nicking the shell on the way in causing a nose up left side jam. Cheap part. Maybe 10-12 bucks. It might be the pbr has a slightly different shape making things worse. These guns should be very tolerant of different loads. This would explain your empty left in the breach face. Also the gen4 RSA seem to be stiffer than gen 3's. Most of gen3 that have feed RSA problems are with stiffer springs. You might try leaving the gun locked back for few days to lossen it up

I might just go ahead and order a new ejector and extractor, just for the hell of it and replace them one at a time.  My problem though isn't an empty being left, it's the new round isn't chambered with the slide in some state of lockback.

[chucky2]

Failure to extract/eject could be the RSA as mentioned.

I would contact Glock before your warranty gets too far out of expiration. Let them try to figure it out for you. You still may be a candidate for a replacement gun.

Going to try and go shooting today and I'll bring all of my Underwood...will be interesting to see if the problem gets worse, better, or the same.  Based on that I'll call the guy on Tuesday, didn't get a chance to shoot this weekend.

[chucky2]

Also interesting that another user is having issues like mine, here's his thread:  http://10mm-firearms.com/10mm-semi-auto-handguns/glock-20-gen-4/.  A little different setup, but pretty much the same.

[PandaBear]

Are you having FTFeed issues with only the last round of the magazine? That is the only problem I am having with mine and very well could be magazine related, but I will know for sure after my next range trip.

Someone suggested replacing the slide stop lever and slide lock spring. I did add an extended slide stop lever, but that didn't fix the problem. Before my last range trip, I removed the slide lock spring to examine it and reinstalled it. Didn't have any issues, but I only had time to fire off 10 rounds using my brand new 10 round magazine.

[chucky2]

No, not limited to the last round but I don't remember it ever being the first 2-4 rounds, it's always the latter half of the mag...I always just load 10, easier I think loading that way.

[The_Shadow]

I might just go ahead and order a new ejector and extractor, just for the hell of it and replace them one at a time.  My problem though isn't an empty being left, it's the new round isn't chambered with the slide in some state of lockback.

Although the empty is being kicked out, is it being held too long, is what I was trying to suggest.  Being held tightly by the extractor against the breech face, and it not allowing the next fresh round from being guided to the chamber so to speak.  It is striking the ejector with force, but can be held until the slide closes to knock it completely out of the ejection port.

This is why I was suggesting to slide an empty casing under the extractor to check the fit against the breech.  You can even cycle empty brass from the magazine to study if they will feed and extract by hand looking for snags or hang ups.

Have you collected some of your brass, to see if it has dents or nicks or damage to them?

[chucky2]

I have literally one spent 10mm casing.  I can always buy another box of Remington 180gr, shoot that, save some casings, and also shoot some more PBR and the Underwood, just to compare ejected casings.  I will check once I get some spent brass.

[chucky2]

Went to a gun show this weekend with my bud, they had a Glock armorer there.  He took all my mags apart and looked at my G20 and noticed two things:

1.)  Mag springs on all of them were about an inch shorter than they should be.  He stretched them out from the middle outwards.  I don't store ammo in my mags, I don't even pre-load them before going to the range, and I hardly even load more than 10 rounds at a time.
2.)  Said not to run FrogLube in it, gets into everything (not sure I believe this, I read of lots and lots of guys running it in their Glocks, no problems).  Not only that, but when Glock sent my pistol back, they said they clean and lubed it...and I believe them.  It was very...non FrogLube feeling.  It was like completely dry, not slick feeling at all.  He cleaned it a little with a baby wipe and long q tip, greased the slide rails with Tetra.

So after the gun show we shot and I ran 100rds of the same PBR ammo, 10 rounds in the mags at a time, as I've been running.  1 FTF.  Prior to this I'd have had like 10 FTF.  Ran maybe 40 rounds of Underwood 135 and 165 grain.  1 FTF.  Made sure to save some spent brass this time.

He said the springs were supposed to be 6 inches long, starting from the point of the V on the first coil to the end of the spring.

One other thing that I thought interesting:  I don't know how pre-Gen4 mags go as far as the inner workings of the mag, however, he was paying particular attention to what looked like binding of my mags as they got up closer to the top of the mag.  He even went and checked another Gen4 G20 mag he had there, it did the same thing so he pronounced it normal.  But the reason he went and checked was because it did not appear normal to him.  I'd be interested in hearing from pre-Gen4 guys on how the piece the bullet sits on in the mag moves from say an inch from the top of the mag to the top of the mag.  Is there any binding or hangup at all?  It'd be something if these new Gen4 mags that are at least a little different in supporting ambi-mag release have some kind of imperfection in (some of?) them that is sometimes creating a less than smooth progression of the bullet upwards.  Might be another reason to explain why it's just us Gen4 guys having problems...