Glock 17 gen4 Endurance Test: Week 5

22-Apr-11 – 22:52 by ToddG


8,378 rounds 5 stoppages
(+1 w/non-LCI extractor)
0 malfunctions 0 parts breakages

Some major milestones this week. First, the pistol is just shy of 5,000 rounds with the latest — 3rd — extractor without any ejection failures. While some gen4 9mm owners have reported extraction/ejection issues beginning a couple thousand rounds into service life, by this point we are probably out of the woods. The only remaining question was whether a new recoil spring would cause a return of the problems. Which leads us to the next milestone…

The G17 had its first parts replacement this week, which consisted of changing out just the recoil spring assembly at 7,677 rounds (7,500 is the recommended interval). So the G17 gen4 has fired 601 rounds with the brand new recoil spring. Any fears that a new full-tension spring would compromise the gun’s reliability appear unfounded.

The G17 did experience a misfire this week with American Eagle 124gr Non-Toxic TMJ. This same lot of ammo caused similar issues back when I tested the P30 in 2009 and as such, the ammo takes the blame, not the gun so it is not counted in the tally above.

My shooting this week was nothing to write home about. Best F.A.S.T. of the week was:

  • 4.90 c: 1.54,.38/1.99/.44,.28,.27

That was the only one (of six tries over two sessions) that came in clean under five seconds. I had a 4.72 with a head shot down, and four clean runs ranging from 5.05 to 5.88 seconds.

I shot Dot Torture at seven yards and scored a 48. Then I decided to try it at 10 yards and scored an embarrassing 39! If there is one area where the Hackathorn i-dot Pro sights from Ameriglo are really giving me some trouble, it is with small targets at close to medium range. I’m not convinced it’s really the sights at this point, though, as I’ve had better success with them in previous weeks. Over the next week I’ll do some more DotTor and similar drills to get a better picture. Of course, if I had a backup gun I could put other sights on it for a side by side comparison, but Glock still hasn’t replaced my broken G19 from ten weeks ago.

The fantastic 99 Drill (by JodyH) using the 3×5 of a Q-PT target turned in identical scores of 87 both sessions. That’s a drop from the 90 I scored the first time I shot it with my HK45. This has become one of my absolute favorite easy-to-use shooting tests. It combines enough reps to be decent practice with PAR times that give at least a fighting chance at shooting a perfect score.

One thing I forgot to mention last week: I went back to the standard coil trigger return spring to get my trigger pull weight down. It was measuring over 8 pounds with the minus connector and NY1 trigger spring in combination with the abominable gen4 trigger bar. It was so bad that when Ken Hackathorn fired the first-ever shot through a gun with “the gadget” his first comment was “that has to be the worst trigger I’ve ever felt” or words to that effect. Marketing fail, Todd.

Bowing to such peer pressure I swapped back to the -/std which, with the utterly abominable gen4 trigger bar, turns in a trigger pull that is still around 6 pounds. The break has much more creep now, and I am toying with the idea of going back to the NY1 spring. Part of me thinks that the problems I’m perceiving with the Hack i-dot sights are actually just related to the lighter but less precise trigger.

What I would really like to do is put in a gen3 trigger bar, but that seems contrary to the point of the gen4 test. Dear Glock, please stop fixing things that aren’t broken. I’d kill for the fabled minus-minus connector, which would make all my problems go away (hint, hint Glock).

I’ll let you know what I’ve decided next week.

Train hard & stay safe! ToddG

Previous Glock 17 gen4 Endurance Test posts at

  1. 28 Responses to “Glock 17 gen4 Endurance Test: Week 5”

  2. Why not just file off the new protrusion from the right side of the tigger bar? Less friction means less trigger weight and a trigger more like the Gen 3’s.

    By Emanuel on Apr 23, 2011

  3. First the FTE issues, now complaints about the trigger bar… makes me wonder what the heck Glock was thinking when they designed the Gen4.

    By MichaelD on Apr 23, 2011

  4. Great report. Agree with sticking with the Gen 4 trigger bar. Sink or swim. They don’t bother me but they bother LOTs of folks. I’d guess that heavy trigger set up is more to blame than the sights.
    I just screwed one of those Ameriglo Hack front sights onto a Gen 4 G19 that’s got Warren Sevigny carry rears. The Warren front was .215 and this Hack front is .220 tall so I think they’ll work. Just a handful of 124 gr +P indicated close POA=POI or just a skosh low at 25 yds.
    I much prefer the just somewhat tighter rear window this offers for a we bit more precision. IMO there is still plenty of space/light on the sight for fast work but this is all in dry fire. Tomorrow I will drill with them.

    By JoeC on Apr 23, 2011

  5. Trigger setup that works for me in G23 Gen 4 (after trying a LOT of different combos and aftermarket parts):

    Stock trigger bar, 3.5 Performance Connector and Overtravel Stop housing, Wolff extra power trigger spring. Light enough, smooth, good reset.

    I tried a Gen 3 G17 trigger bar (with no “dimple”), but it did not seem to fit right. Strange feel and some reset problems. Never live fired with it b/c I’d read online of a few isolated reports of doubling with Gen 3 bar in Gen 4. The geometry of the bars is definitely different, it’s not just the dimple. Engagement with the striker in Gen 4 is greater than in previous gens, which may contribute to a harder break. Using a reduced power striker spring definitely helps the trigger weight (combined with stock connector, OT stop and reduced pre-travel trigger, comes closest to 1911 as I’ve felt in a Glock), but I don’t want to go there on a serious gun (risk of light strikes). Other things I’ve tried: Fulcrum Gen 4 trigger bar (thought it would cure my Glock Blister but no dice, just gotta man up!) and connector, Gen 4 trigger bar, Ghost Tactical connector, Vanek 3.5 connector, possibly some other stuff. YMMV.

    By AK on Apr 23, 2011

  6. When do you plan to replace the slide lock spring? When it breaks?

    By James V on Apr 23, 2011

  7. what is the “fabled minus-minus connector”? I’ve heard of one minus…but not two?

    By Dick M on Apr 23, 2011

  8. It’s a super secret squirrel trigger bar.. They’re allegedly for certain military and federal special units. The minus minus is probably the first name to it. I doubt we’d ever get to see one.

    By Sean on Apr 23, 2011

  9. A trigger bar? Not a minus minus connector?

    By JoeC on Apr 23, 2011

  10. The only difference I’ve noticed between Gen 3 & 4 trigger bars are where the reset spring hooks onto it. Otherwise it looked exactly the same.

    By Emanuel on Apr 24, 2011

  11. Todd – I appreciate that you post the ups and downs of your training progress, and aren’t afraid to admit mistakes. Your ‘bad’ FAST times are still better than my best times.

    It’s interesting to hear about other folks gaining and losing ground as time progresses, it’s not always two steps forward, at least for me.

    By James V on Apr 24, 2011

  12. JoeC,

    I had trigger bar on the mind.. I meant connector.

    By Sean on Apr 24, 2011

  13. Todd, Glad to see you are continuing the test. A lot of Glock-haters would probably like you to call it quits and put it down in the books as the gen4 g17 being a failure.

    Let the results stand for what they are. Good job!.

    By Yeo on Apr 24, 2011

  14. Todd:

    I bought a used Gen 4 G22 with a NY1 trigger spring. It had the worst trigger ever felt (well, except for most military 1911’s in the 1970’s and 80’s, but that is another story). Measured almost 14 pounds.

    Putting in a minus connector helped as it went down, like your G-17, to around 8 lbs. Putting in a Gen 3 trigger bar got it down to slightly less than 7 pounds. It’s a bit squishy before it breaks, but not too bad. Since I don’t use it for target shooting I find it acceptable.

    I like the Gen 4 quite a bit–but they weren’t ready for prime time when Glock released them.

    By SteveJ on Apr 24, 2011

  15. A friend (TJ) recently got a Gen 4 17 and it had the most absolutely worst trigger on any Glock I have ever felt. Before shooting it, we detail stipped it, cleaned it up, took a little sandpaper and did a bit of a trigger job on the contact surfaces, left the bump (for now) and relubed it. Trigger was 100% better. What a world of difference. That bump will be coming off soon but he wanted someone else to try it first.

    By Emanuel on Apr 25, 2011

  16. Gen 4 Glocks were certainly over sprung initially and maybe still. I have found (along with others) that the pencil point ejector may be the (probably is) the source of most of the ejection issues. removing .025 – .040″ of the ejector cures the ejection problems in all of the problematic Glocks that I have seen. The 0 4 1 G19 spring seems good to go, in the one sample that I have tested it is lighter than the 0 4 springs that I have on hand.

    By mike benedict on Apr 27, 2011

  17. Mike: Where do you remove the metal on the ejector? Thanks.

    By SteveJ on Apr 27, 2011

  18. Steve from the point of the ejector. The part that hits the case.
    If you look at the ejector under a magnifier you will see that it is not flat. In my opinion it need a wider flatter surface to eject properly. One of my G4 19s ejected poorly with cases hitting me in the face, going over my head and every other direction imaginable. After I filed the ejector all empty cases went to the right and slightly back. Which is perfect

    By mike benedict on Apr 27, 2011

  19. Mike: Thanks. I am going to try that on a Gen 4 G23 I have that is having all kinds of problems–including spitting cases into my face.

    By SteveJ on Apr 28, 2011

  20. Mike:

    You are a genius. I took a file to the ejector of my Gen 4 G23, which had 15 FTE’s and unlimited weak ejections in the first 1000 rounds. I made sure not to take off too much metal, but enough to increase the contact surface. A new extractor had not helped.

    The result was 200 trouble free rounds tonight. I will keep testing it, but I think that you have found at least one solution to the issues raised by the stiffer spring of the Gen 4.

    Todd, if you are still reading these comments you might want to go back and read Mike Benedict’s posts. While your new extractor seems to have solved your problem, Mike’s simple ejector fix might also do the trick.

    By SteveJ on Apr 28, 2011

  21. SteveJ — The ejector as possible culprit (or at least cohort) in all of the gen4 9mm problems first came to light, to the best of my knowledge, by Dave Harrington while he was at Rogers Shooting School recently. Dave and Bill (Rogers) have been in contact with Glock about it. We’ll see where it goes from there.

    At least one friend of mine tried modifying his ejector in this way and his gen4 G19 still had stovepipe problems. So it doesn’t appear to be a 100% solution.

    By ToddG on Apr 29, 2011

  22. Todd:

    That is very interesting. The same ejectors, of course, work fine on Gen. 3’s. My guess is that the stronger springs on the Gen 4’s are slowing down the slide’s movement enough that often the ejectors (and at least some of the extractors )are not functioning properly.

    The problem is biggest with the 9 mm’s. Most work fine, but a material percentage don’t. The overwhelming majority of the 40’s are good because of the greater recoil, but a small percentage (perhaps with small manufacturing imperfections in the slide rails) such as my G-23 have FTE troubles.

    My guess would be that a combination of the new springs, new extractors with looser tolerances and a new, less pointed, ejector would solve 99% of the problems.

    The bigger issue, of course, is how could this have happened? Glock obviously has some internal issues it needs to work out. Your reports might help that process along.

    By SteveJ on Apr 29, 2011

  23. SteveJ – I modified my ejector (Gen4 19) and still experienced stovepipes. I tested it with an 04 spring as well as a captured ISMI 18# spring.

    By James V on Apr 29, 2011

  24. James:

    1. Are those “normal” stovepipes or are some like the ones in the photo that Todd posted of his G17 (with the shell caught between the rear of the ejection port and the rear of the chamber/barrel)? I had the latter condition, and perhaps the way the brass is stovepiping might be a clue to what is wrong.

    2. Have you tried a replacement extractor yet?

    Good luck–and let us know if you try a new extractor (I tried that before I filed the ejector down and it didn’t help).

    By SteveJ on Apr 29, 2011

  25. The stovepipes are like this one:

    I’ve tried a new extractor. I replaced the #3 for a looser fitting #4.

    I’ve also tried using a pre LCI spring bearing to increase the extractor spring tension.

    I’ve tried half a dozen different modifications and parts swapping iterations, nothing has fixed it. I sent it back to Glock today.

    By James V on Apr 29, 2011

  26. James:

    Well, that shoots down my theory that the fix is relatively simple. For some Gen4’s it is, but it seems pretty obvious that there must be a basic defect in many of the pistols–which suggests some subtle flaw in the Gen. 4 design (tolerances too tight in the rails?).

    Good luck and let us know how Glock handles the issue.

    By SteveJ on Apr 29, 2011

  27. Todd: you wrote “7,500 is the recommended interval”

    Are there some Glock-official recommendations regarding to periodic pistol maintenance and parts replacement?

    I haven’t found any yet.
    Even our local Glock importer answered me something like “no such official rules exists”.


    By yarco on May 3, 2011

  28. 7,500 is the recommendation Glock makes during armorer school.

    By ToddG on May 3, 2011

  29. And what should be replaced each 7500 rounds?

    – some springs,
    – all springs,
    – some springs and parts,
    – …


    By yarco on May 16, 2011

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