Polymer80 Glock-ish troubleshooting assistance

[cmeilahn]

I have a Polymer80 pf940c build with which I need some assistance troubleshooting the slide actions. Everything cycles fine when empty. With a laser trainer or snap cap/trainer/dummy round, the slide doesn't fully close forward with light slide pulls (ex. chamber check). I'm happy to work with a gunsmith, Glock armorer, experienced builder, etc. to figure this out. I have a 26-ish (pf940sc) build that needed some rail work to get functioning smoothly, but this one has been a bit of a challenge.

Yes, I've gone through dozens of videos, several Glock guides, including an armorers manual, and polished the internals... some multiple times.

We just moved to the area in June. Does anyone have recommendations for someone in the Tulsa area with good knowledge & experience troubleshooting Glocks & Glock-ish builds?

 

[RockHopper]

Welcome to OKS. I'm new here myself, and it seems to be a great place so far!

In my experience, nothing smooths out operation on a new pistol like taking it out and shooting the absolute crap out of it.

I'm not a gunsmith or armorer, but I've put a few together, and been privy to dozens of builds. The most common problem with p-80's is pin misalignment....and the most common mistake, drilling both sides of the pin holes from a single side of the frame. But no matter why, the P-80 jig isn't exactly a precision fit device, even if used only once. If your snap caps will fully seat in the chamber, even if you've gotta give it a smack, than it'll eventually run smooth. You may wear out an extractor prematurely, but that's no big deal.

If you wanted to boost the spring power, you could try an aftermarket spring such as wolf . I use a Glock shop SS set-up that I've been really happy with on my pf940c, which has been my edc for about 2 years now. Looks good and gives a little extra oomph for when I'm running steel cased junk at the range.

 

[MacFromOK]

I have a Polymer80 pf940c build with which I need some assistance troubleshooting the slide actions. Everything cycles fine when empty. With a laser trainer or snap cap/trainer/dummy round, the slide doesn't fully close forward with light slide pulls (ex. chamber check). I'm happy to work with a gunsmith, Glock armorer, experienced builder, etc. to figure this out. I have a 26-ish (pf940sc) build that needed some rail work to get functioning smoothly, but this one has been a bit of a challenge.

Yes, I've gone through dozens of videos, several Glock guides, including an armorers manual, and polished the internals... some multiple times.

We just moved to the area in June. Does anyone have recommendations for someone in the Tulsa area with good knowledge & experience troubleshooting Glocks & Glock-ish builds?

If you're loading the snap cap/whatever into the chamber by hand, the slide has to push the extractor out to hook on the rim. When loading from the mag, the round slides up under it.

Just a thought. Welcome to OSA.

___

 

[cmeilahn]

If you're loading the snap cap/whatever into the chamber by hand, the slide has to push the extractor out to hook on the rim. When loading from the mag, the round slides up under it.

Just a thought. Welcome to OSA.

___

The laser trainer has to be inserted by hand, but I've run snap caps through with the magazines as well as by hand. I tried 1, 2, 5, 10 and 15 rounds in the magazine... All with the same results.

Initially, there were issues with the dummy rounds loading in and ejecting reliably. After I checked & fixed the rail alignment and re-polished everything, the action went smoothly with a full slide pull-back & release.

 

[cmeilahn]

Welcome to OKS. I'm new here myself, and it seems to be a great place so far!

In my experience, nothing smooths out operation on a new pistol like taking it out and shooting the absolute crap out of it.

I'm not a gunsmith or armorer, but I've put a few together, and been privy to dozens of builds. The most common problem with p-80's is pin misalignment....and the most common mistake, drilling both sides of the pin holes from a single side of the frame. But no matter why, the P-80 jig isn't exactly a precision fit device, even if used only once. If your snap caps will fully seat in the chamber, even if you've gotta give it a smack, than it'll eventually run smooth. You may wear out an extractor prematurely, but that's no big deal.

If you wanted to boost the spring power, you could try an aftermarket spring such as wolf . I use a Glock shop SS set-up that I've been really happy with on my pf940c, which has been my edc for about 2 years now. Looks good and gives a little extra oomph for when I'm running steel cased junk at the range.

I agree about the pins and the jig. The jig is (1) a pain, and (2) not very precise, and the result is the pins don't always line up well. My next 19-ish build is going to be a Lone Wolf. On this build, I used a hand drill per the build instructions. On my subcompact build I used a dremel & press. The pin holes in this one are rougher, but still line up fairly well... though not 100%, for sure. The rear trigger housing pin & rail assembly setup were a bit off.

I tried replacing the P80 plastic recoil spring assembly with a stainless one from Rockey Brass with the standard OEM spring strength. It didn't make much impact, but did identify another issue... I had a bit of a nik in the recoil spring channel. After I smoothed that out, it stopped catching. I may get a higher strength recoil spring, but I'm not convinced that's the problem. However, it is a bit smoother with the original and the replacement seems a bit off.

I tried a few different extractors, including the P80 one that came with the slide, an OEM gen3 extractor, and a Rockey Brass failure resistant extractor. All have the same result.

I upgraded the ejector from a gen3 to a gen4, again with no change... but I did that before the first real shots and I wouldn't expect a change to slide closure from the ejector, just the extractor.

My suspicion is with the springs. Specifically the firing pin safety spring or the extractor depressor plunger spring... possibly the extractor depressor plunger & bearing too.

In the case of this build, I only have about 60 rounds through it so far. And the issue seems to be getting "worse". I want to get it figured out without spending too much more, but maybe a full set of new springs would help.

 

[Garrus Vakarian]

I has this exact issue. It was my breachface that was out of spec and had a small lip that was catching the edge of the brass.

I good polishing later and no more issues

 

[cmeilahn]

I has this exact issue. It was my breachface that was out of spec and had a small lip that was catching the edge of the brass.

I good polishing later and no more issues

I checked the breech face and barrel feed ramp, but didn't see or feel anything that would catch. I did go ahead and do a little work on the breech face in hopes that it would make a difference. But, sadly, no joy. Thanks for the idea!

 

[dlbleak]

Welcome @cmeilahn. I’m in no way a Glock or 80% guru. Looks like these guys will help you figger it out. Good luck!

 

[cmeilahn]

I had the bright idea to try the slide from my other build that's waiting on me. It had similar issues, which mostly pointed to the frame and lower components as the main culprits, but a couple items on the slide too. I made a few adjustments (below), and the action smoothed out nicely. After 1-4 were done and "set", I went ahead and replaced the firing pin spring, firing pin safety spring, connector and trigger spring with a lower trigger-pull weight, and then the extractor depressor assembly. Now the trigger is like butter too, and the LCI works as expected and the brass ejection is much more consistent.

So here are a few things I did, and each had some impact, with the first having the most, and each successively less:
1) Frame: Additional sanding & re-polishing the recoil spring channel in the frame (it was already down to the spec/etched cutout lines of the blank & smooth, I brought it a little "lower" and polished it smooth again. Before doing this, results were the same with each of the recoil spring assemblies.
2) Frame: Additional shaping and polishing of the trigger bar "fin" - to round it out a little bit more than spec.
3) Slide: Additional "smoothing" and polishing the firing pin safety plunger - to round the top edge a little more than spec.
4) Slide: Tried a couple different recoil spring assemblies... the one I've been using was the worst of the 3... After looking at it, I think it may have a G19 bar with G17 spring... the spring is super-wavy, whereas the other 2 are "straight" when "neutral"
5) Frame: Trigger spring changes... this made the whole action a lot smoother and "lighter" overall
6) Slide: Extractor depressor assembly... this was mainly to fix some issues I had with erratic extraction and the loaded chamber indicator not presenting well, not so much the action.