Help diagnosing some odd failures in a G17

[Nephrology]

I traded for a G17RTF manufactured sometime in 2009 (Feb? forget when, I looked it up a while ago) and it is a fantastic pistol. Despite the fearmongering over the new style G17 extractor, mine has no issues with extraction, at least. Every round is cleared at ~4 o'clock, no weak brass in my face, etc. Has just north of 2k rounds through it.

HOWEVER, I HAVE had very odd issues with failures to return to battery. I am a certified Glock armorer and what they recommend (clean mating areas between barrel/slide/frame and replace RSA). Still has not 100% resolved the problem. It fails the vertical return to battery test (point cleared pistol at 45 degree angle upwards, depress trigger, retract slide and slowly let the slide forward).

I really do not have any idea why. It is mildly dirty - it just recently completed the 2k round challenge (well, completed aside from ~7 FTRTBs) and so I gave it a . I lubricated the barrel and locking lugs and that helped, but still recently had 1 FTRTB.

Now, the gun is not in 100% NIB condition - still kind of dirty, mostly dry - but I expect Glocks to be able to function like this. My g19 and G26 have been flawless. I can't quite explain what is causing this. It is not the RSA - I swapped that out and the failures persisted.

Any thoughts? I think there must be some dimension that is off. I feel like when the barrel initially unlocks, it travels a little bit further rearward than my G19 (perhaps slide dimensions?). It usually hangs up just before the barrel is supposed to tilt forward and go into battery.

Any thoughts? This is not an easy problem to diagnose. I will probably just call Glock at some point, but given the infrequency of these malfunctions (less than 1% of all fired shots) I am not sure I want to bother them just yet.

edit: All failures occured with el cheapo puffball 115gr practice ammo (UMC, Wolf, etc). Cycles the zippier 124gr Geco FMJ just fine, as it does every defensive JHP i've thrown at it (147gr Golden Sabers, 115gr +P DPX, Hydrashok, etc). However this is my primary competition pistol and I want it to be able to eat everything i throw at it. Everything.

[sboza]

Brother, from one glock armorer to another, clean the entire gun. Cleaning mating surfaces should solve the problem if you actually get every mating surface. Glocks run well mostly dry but gunk buildup can obviously cause a failure to go into battery and crap ammo exacerbates this. It seems silly to me to return the gun without giving it a proper scrub. Let me know what happens after you do so and we can eliminate that possibility.

[dwhitehorne]

I just went back through the Glock course about three weeks ago. They said something about originally having the same full size recoil spring for the 9,40 and 357. Glock now has a different spring for the 9mm since they said the 40/357 spring was too stiff. Maybe it is the reason for your issues with the lighter loads??

Glock also said they have changed the way they mill the front of the slide where the recoil assembly sits. I got an adendum to the armorers manual for the 4th generation Glock changes and part numbers. I would call your regional Glock rep you should have met in the amorers course and get the updates. Good luck. David

[sboza]

I just went back through the Glock course about three weeks ago. They said something about originally having the same full size recoil spring for the 9,40 and 357. Glock now has a different spring for the 9mm since they said the 40/357 spring was too stiff. Maybe it is the reason for your issues with the lighter loads??

Glock also said they have changed the way they mill the front of the slide where the recoil assembly sits. I got an adendum to the armorers manual for the 4th generation Glock changes and part numbers. I would call your regional Glock rep you should have met in the amorers course and get the updates. Good luck. David

I am pretty sure that the recoil spring issue for the 9mm vs .40 s&w and .357 sig is regarding gen 4 glocks. The op said his is a g17 rtf, which I believe is gen 3 only. Could be wrong but I'm fairly confident that this is the case.

I stand by the give the gun a good cleaning and see if the slide still fails the test.

Btw, are you running a pistol light?

[Nephrology]

I am pretty sure that the recoil spring issue for the 9mm vs .40 s&w and .357 sig is regarding gen 4 glocks. The op said his is a g17 rtf, which I believe is gen 3 only. Could be wrong but I'm fairly confident that this is the case.

I stand by the give the gun a good cleaning and see if the slide still fails the test.

Btw, are you running a pistol light?

Correct, it is a Gen 3. And no, I was not running a pistol light when these failures occurred- in fact I think the one time that I did shoot it with a light on it performed 100%.

I will give it a good scrub down. it definitely helped when I lubricated the barrel. I suspect part of it could be the finish - it is the gray, parkerized looking finish as opposed to the smoother darker black finish. I think it might have been a little thick , causing it to bind up against the roof of the slide when I was shooting it dry.

I will do a thorough cleaning and report back later. Unfortunately my schedule doesnt look like it will permit lots of shooting soon (just relocated cross country), but I will get out when I can.

[sboza]

Good deal brother. Hopefully it's just a bit of gunk somewhere it shouldn't be but if it's anything more I'm sure glock will do you right. I'm nit crazy about the grey finished parts either. But glock is making more pistols here now and we were told that the exact tennifer process couldn't be replicated here due to our stricter environmental laws. Good luck with the unpacking.

[Nephrology]

Good deal brother. Hopefully it's just a bit of gunk somewhere it shouldn't be but if it's anything more I'm sure glock will do you right. I'm nit crazy about the grey finished parts either. But glock is making more pistols here now and we were told that the exact tennifer process couldn't be replicated here due to our stricter environmental laws. Good luck with the unpacking.

Thanks man, I really appreciate the advice. Yeah - I suspect perhaps it was finished here instead of in Austria. Perhaps it was slightly too thick. My hope was that if I shoot it enough the finish on the barrel/roof of the slide will wear down to the point that it is no longer an issue.

And yeah I will NEED the help unpacking.... though it did give me an excuse to buy a bunch of ammo!

[Beat Trash]

I recently detailed stripped a highly reliable Gen3 Glock 19. After putting everything back together, I started having issues as described by the OP.

What I found to be the issue was the spring inside of the firing pin safety plunger. When installing this spring, you need to rotate it to "lock" it into the plunger. Failing to do this caused the spring to be off a bit.

I found this when the slide was off. I pushed down on the firing pin safety plunger and felt a slight bit of momentary resistance. This was causing the slide to not go into battery every time.

Have you checked this? I bring it up since the gun is used. Someone could have taken it apart and not properly put it back together.

[JonInWA]

Additionally, I'd simply replace the recoil spring assembly and the magazine spring(s) with new ones at this time; they're dirt-cheap and by doing so you'll be easily eliminating another potential causal factor.

I'd also check your spring loaded bearing assembly and extractor.

Best, Jon

[Nephrology]

Additionally, I'd simply replace the recoil spring assembly and the magazine spring(s) with new ones at this time; they're dirt-cheap and by doing so you'll be easily eliminating another potential causal factor.

I'd also check your spring loaded bearing assembly and extractor.

Best, Jon

RSA is brand new (both of them, initial and replacement). mags are also brand new. EDP bearing has been replaced, not the spring though... i dont really see how the extractor would cause FTRTB...?

I will check the firing pin safety spring however that seems like it may be a otential source of malfunctions.