Glock 17 gen4 Endurance Test: Week Two

1-Apr-11 – 11:18 by ToddG
5,047 rounds 5 stoppages
(+1 w/non-LCI extractor)
0 malfunctions 0 parts breakages

During the combined Speed Kills/Get SOM class in Seattle last weekend, the G17 had another extraction failure, this time with the “obsolete” extractor and companion spring loaded bearing. The stoppage occurred in front of the whole class near the end of the first day’s Dot Torture exercise. Ammo was 115gr Blazer FMJ. The pistol fired another 275 or so rounds after that without incident, but my faith in the “fix” was over.

As you can see above, I’ve called out that stoppage separate from the rest. I agonized over whether or not to count the stoppage with the older (“obsolete”) extractor against the gun. It’s not a current factory part. It wouldn’t be installed if the gun went back for warranty repair. But at the same time, all those rounds through the gun count, so the stoppage should probably count, too. In the end, I decided to detail the specifics in the weekly stats and let each reader interpret the data for himself.

After the stoppage, calls were made and a couple days later the Extractor Fairy delivered a few different extractors to world command headquarters. Two were brand new current production extractors (one marked “1” and the other marked “3”), and two were older pre-LCI style. I dropped the “1” and “3” each into the slide to see which would fall out freely, and the “3” was the winner. Admittedly, there may also have been a little bias since this is now the third extractor the gun has tried in two weeks. I put that extractor in the gun and vowed that either the pistol would finally be reliable or I’d give up on the test altogether. I also installed a new (current production) spring loaded bearing, extractor depressor plunger, and extractor depressor plunger spring (i.e., the whole extractor assembly).

I’m happy to report that 1,631 rounds later the pistol has not had any stoppages. Ammo used has been Blazer 115gr FMJ, American Eagle 124gr FMJ, and Federal 124gr +p HST. The G17 hasn’t been cleaned or lubricated since I installed the new extractor and if all goes according to plan, it should finish the 2,000 Round Challenge by the end of this weekend’s Aim Fast Hit Fast class in College Park, TX.

While I had the gun apart to replace the extractor, I also installed the Glockmeister gen4 grip plug (pictured right) on the advice of my buddy JV. Instantly, my reloads improved… a lot. Without the plug I’d frequently get the mag jammed into the hollow behind the magwell requiring what seemed like an eternity to reorient and insert. This is not an uncommon complaint, especially with the gen4 guns.

Comparing last week’s “50 FAST” runs, I had eighteen out of fifty reloads fumbled at over two seconds with a worst of 2.82 seconds then. This week it was three out of fifty with a worst of 2.07 seconds. The improvement is obvious and substantial. The Glockmeister gen4 plug is a must-have as far as I’m concerned. (I am in no way associated with Glockmeister and I bought mine over the internet through their online store)

Full results of the “50 FAST” exercise:

HK 45: 27-Oct-2010 G17: 24-Mar-2011 G17: 30-Mar-2011
Average (total) 5.46 5.50 5.12
Average (raw time) 4.50 4.66 4.30
Best run 4.14 4.21 3.92
Worst run 8.46 8.69 8.84
Head hits 80% 83% 83%
Body hits 98% 98% 96.5%
Draw (avg) 1.43 1.56 1.44
Head split (avg) 0.45 0.45 0.40
Reload (avg) 1.94 2.01 1.82
Body splits (avg) 0.23 0.21 0.21

Of course, only the first three F.A.S.T. scores in a day normally count. The exception is when I run more than three in a row that are clean under five seconds. Wednesday night I did four in a row:

  • 4.53 (c): 1.59, .42 / 1.93 / .20, .20, .19
  • 4.22 (c): 1.40, .37 / 1.86 / .21, .19, .19
  • 4.37 (c): 1.51, .46 / 1.85 / .19, .20, .16
  • 4.37 (c): 1.51, .44 / 1.81 / .22, .20, .19
  • 5.49 (-1 body): 1.52, .40 / 1.94 / .22, .21, .20

Thursday night I had JV run the timer for me, and of three runs only one was clean (4.50). I had a 4.98 and a 4.14, each with one head shot missed.

I also played around a bit with the Hackathorn/i-dot sights some more. This week, I worked on determining where my point of impact would be for various distances given either a “dot” or top edge point of aim. Because I’m most concerned with where my carry ammo prints, I used the Federal 124gr +p HST and got the following results from five shot groups:

  • at 50 feet using the dot as point of aim, all shots fell within the 6″ circle on a Q-PT target.
  • at 75 feet using the dot as point of aim, all shots fell within the 8″ circle, clustered around the border between the 6″ and 8″ zones.
  • at 100 feet using the dot as the point of aim, two shots were in the 6″, two were in the 8″, and one was about two inches above the circle.
  • at 100 feet using the top edge as the point of aim, all shots were in the 6″ circle.
  • at 150 feet using the dot as the point of aim, all of the shots went high and left of the circles.
  • at 150 feet using the top edge as the point of aim, two were in the 6″, two were in the 8″, and one was about four inches to the left of the circles.

Between that experiment and shooting at the 3×5 out to 25yd, I’ve come to the conclusion that up until the big orange Hackathorn front sight completely obscures the target zone, the dot can be used as the point of aim. Once the dot is larger than the target zone, the top edge is a better choice. I’ve also determined that my rear sight needs a little tweaking to the right to compensate for about 2″ of windage at 25yd. Luckily, the Glock Sight Tool Gnome has one on the way to me already.

See you next week… hopefully.

Train hard & stay safe! ToddG

(Third Time’s A Charm graphic borrowed from

Previous Glock 17 gen4 Endurance Test posts at

  1. 19 Responses to “Glock 17 gen4 Endurance Test: Week Two”

  2. Hope you finally got it worked out. My first gun was a 9mm Glock and I hate to watch them ruin the reputation they’ve built in such a short period of time.

    By Billy Ng on Apr 1, 2011

  3. It just seems amazing to me that Glock didn’t do the proper research and testing to iron out these issues before releasing the 4thGen guns. They built there reputation on utterly reliable guns and now that seems shaken. I’ve run several generation 2 and 3 guns without an issue but don’t think I would ever purchase a generation 4.

    By SteveK on Apr 1, 2011

  4. The interesting thing is that this really seems to be plaguing the 9MM more than the .40… I’ve heard far fewer complaints with the .40’s.

    I wonder if they target the .40 for more development/testing since their aggressive marketing to LE?

    By Les on Apr 1, 2011

  5. WOW! Glock use to be the standard for reliability in the polymer arena. It was the gold standard for dependability! I am shock but not surprised. S&W and HK have been bringing out so very good pistols lately. I would love to see you guys do an XDm test next! I am not a fan because of the high bore axis but I still like the gun quite a bit!

    By Soapboxpreacher on Apr 1, 2011

  6. Is it your EDC gun now?

    When do we get a carry report?

    By AfterWork_Ninja on Apr 1, 2011

  7. So, if I understand the data correctly and memory serves me right, you already beat your best HK P30 F.A.S.T time, or that 3.92 doesn’t count for some reason?

    By YK on Apr 1, 2011

  8. So this could really explain why some Gen4 17’s run fine and some don’t run worth a hoot.
    Sounds like some one at Glock need to get on the ball.

    By Prdator on Apr 1, 2011

  9. Every gun manufacturer has some lemons or some kind of issues. I don’t see a real reason to abandon this test. Figure out what’s wrong fix it and continue. I’ve stated it before MDPD is giving out the gen 4 G17 to all sworn personnel who want them and I’ve yet to see any major issues even with under powered practice ammo. So far they have been shown to be very reliable. These are the latest versions with springs and counter bore.

    By Frank on Apr 1, 2011

  10. Todd do you still think that the issue is the extractor or could it be that the recoil spring is starting to soften up?

    By Kirk in Utah on Apr 1, 2011

  11. AfterWork_Ninja: Yes, though candidly I admit it may be jumping the gun (pun intended). My optimism outweighs my skepticism.

    YK: The 3.92 wasn’t a legitimate (first three of the day, or part of an unbroken string of sub-5 clean) run.

    Kirk: Anything is possible, but I doubt it. Heck of a coincidence that the extractor changes would coincide with such immediate improvements in reliability. At 7,500 I’ll replace the recoil spring and we’ll see if problems suddenly reappear.

    By ToddG on Apr 2, 2011

  12. Todd, PM sent via pistol-training forum re original extractor.

    By JoeC on Apr 2, 2011

  13. I wonder if Glock is subcontracting out the extractor manufacturing.

    By JSGlock34 on Apr 2, 2011

  14. I was told that Glock outsources the extractor, springs, and locking block. The extractor and locking block are supposed to be MIM. Perhaps that’s why they can’t do them in house.

    By James V on Apr 2, 2011

  15. Glock G17 has been my all time favorite

    By Martin Claybold on Apr 3, 2011

  16. Todd, we used to use the Glockmeister butt plut–they work well, but we found the Scherer slug plug to be even better, especially in regards to aiding magazine changes: [url][/url].

    By DocGKR on Apr 3, 2011

  17. awesome shooting with you this weekend. But it was College Station, TX…not College Park. I know your a stickler for details. Insert smiley face.

    By Chris on Apr 3, 2011

  18. Chris — Doh! Of course you’re correct. Back home it’s College Park (MD). Thanks! Great shooting with you this weekend, as well. Awesome job on the head shot standards!

    By ToddG on Apr 3, 2011

  19. Les mentioned above that .40 cal Gen 4’s don’t seem to be having the problems of the 9 mms.

    Maybe that is correct, but one reason that I am following this closely is because I have a Gen 4 G 23 that has had multiple FTF/FTE issues, including stove pipes. I also have an early Gen 4 G 23 that reacted badly to a mounted light.

    There is a lot to like about the Gen 4, but it is clear to me that the problems go well beyond the 9 mm’s. As I’ve mentioned before, I think their tolerances are probably too tight.

    Anyway, I now need to find an “Extractor Fairy” to provide me a better extractor for my G23. Any ideas on where to find one, Todd?

    By SteveJ on Apr 5, 2011

  20. Best advice I can offer is to contact Glock and ask for a replacement extractor.

    By ToddG on Apr 5, 2011

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