Glock 17 gen4 Endurance Test: Week 11

3-Jun-11 – 18:32 by ToddG

16,312 rounds 6 stoppages
(+1 w/non-LCI extractor)
0 malfunctions 0 parts breakages

Lots going on this week with the test:

  • After #14,292 the G17 was detail stripped and cleaned.
  • After #15,093 the G17 had a new recoil spring (0-2-1) and slide lock spring installed.
  • At #16,030 the G17 had a failure to feed, pictured above. The round appeared normal and chambered just fine on a second attempt.

The failure to feed is the first stoppage the pistol has experienced since putting the latest extractor in the gun almost thirteen thousand rounds ago. Nobody wants to see a stoppage of any kind in his carry gun, but realistically if you run a gun hard it is eventually going to have bobbles. In the grand scheme of things, a Mean Rounds Between Stoppage of 13,000 would be acceptable by anyone’s standards.

As mentioned, I replaced the recoil spring assembly per plan at about 7,500 rounds. What I didn’t expect to see, however, was the 0-1-1 recoil spring intended for .40-cal Glocks that had apparently been in the test gun for that 7,500 rounds. A 0-1-1 must have been accidentally in the package of springs I received and I never noticed the designation until removing it for replacement this week. Noteworthy that the “too-heavy” spring — which many have assumed was the cause of the gen4 Glock reliability issues — ran like a champ in my gun, isn’t it?

Another major event this week involved “the gadget” reaching the 10,000 round mark without causing any issues with the gun or suffering any breakage. In fact, it does not appear to have any wear or dimensional deformation at all. Tom Jones and I are understandable excited about that!

After whining about how long it took Glock to send me the spare G17… I still haven’t fired a round through it. Next week, I promise!

Train hard & stay safe! ToddG

Previous Glock 17 gen4 Endurance Test posts at

  1. 20 Responses to “Glock 17 gen4 Endurance Test: Week 11”

  2. How long has it been since the last malfunction?

    About a month?

    Mm, PMS indeed… 😀

    By Donovan on Jun 3, 2011

  3. Looks like a magazine issue to me.

    By Kirk in Utah on Jun 3, 2011

  4. You’re 0-1-1 spring is interesting but not so surprising to me as we have two here with the early unmarked RSA which was also .40 weight. So just that the right set up gun will run with those is as I have experienced.

    What have you noticed about scuffing/gouging in that channel where the RSA lives? In the early months of Gen 4 17s hitting the street last year, there was some concern over this. In our guns, they got scuffed a bit in a few hundred rounds but this has not advanced noticeably over following thousands.

    By JoeC on Jun 3, 2011

  5. 1. In another 5,000 rounds you’ll know whether this is just a statistical blip or the start of real problems.

    2. Regardless of how that particular G 17 turns out, 10,000 rounds is a good test on the gadget. Time to widen the circle of beta testers, I think.

    By SteveJ on Jun 3, 2011

  6. FTF is mag spring failure

    By Dandapani on Jun 3, 2011

  7. Kirk & Dandapani — Agreed that if it’s a recurring gun issue it is most likely the magazine. I noted which mag was in the gun when the stoppage occurred. If it produces the same stoppage again, it will get trashed and replaced.

    JoeC — When you say “channel” do you mean in the frame? I detect no marks or wear that I would consider out of the ordinary or noteworthy.

    SteveJ — We’re hoping to get “beta” samples of the gadget into testers’ hands before the end of the year.

    By ToddG on Jun 3, 2011

  8. just curious, where does one look to determine the spring designation? I’ve looked at my G19 spring and can’t find any marking on it.

    By Rob Engh on Jun 4, 2011

  9. Rob,

    It is on the end of the spring on the metal plate pn the grip end of the RSA. If you do not have any markings it is the original that came with the early model GEN 4s.


    By Ga Shooter on Jun 4, 2011

  10. yes, by channel I meant up in the frame where the RSA seats. I don’t know official nomenclature very well. A year ago some seemed concerned the guns would tear themselves apart in this area that got hogged out for the fatter RSA. That concern seems to have died out.

    By JoeC on Jun 4, 2011

  11. One of the early touted advantages of the Gen4’s using the heavier two spring recoil system was less muzzle flip. I would be interested to know if you see much difference with the new lighter spring?

    By JohnN on Jun 4, 2011

  12. Was that a true fails to feed?

    Just asking, because from the angle of the photo it looks more like a bolt-over-base stoppage.

    By chuck on Jun 4, 2011

  13. My G17 doesn’t have a bolt. (g)

    By ToddG on Jun 4, 2011

  14. Let us know if its the mag please.

    By John P. on Jun 5, 2011

  15. FWIW, the same mag was used for almost 600rd worth of shooting since then without a repeat of the problem. I have six training mags and try to use them all equally so that’s ~100rd so far.

    By ToddG on Jun 7, 2011

  16. “One of the early touted advantages of the Gen4?s using the heavier two spring recoil system was less muzzle flip. I would be interested to know if you see much difference with the new lighter spring?”

    Apparently, in some cases the Gen4 design renders the recoil and muzzle flip resulting from the next trigger pull so tame the shooter doesn’t even feel it…..

    By Matt on Jun 7, 2011

  17. “My G17 doesn’t have a bolt. (g)”

    Umm, yeah, knew that, it’s a malf that is rather common on AR platforms, caused by either the mag failing to allow the round to feed up so that it can get hit from behind by the bolt, or the bolt failing to come back far enough to pick up the round properly.

    On a Glock it would be a slide-over-base malfunction.
    Was the breechface behind the base of the brass as it should be, or hitting the middle of the casing was my not so well worded question?

    By Chuck on Jun 8, 2011

  18. Chuck — The bottom edge of the breechface was caught in the extractor groove of the cartridge.

    By ToddG on Jun 9, 2011

  19. Pretty much a “bolt over base”

    Two possibilities;

    Slide short stroked for whatever reason, including possibly an underpowered round.

    Or the mag failed to feed up properly so that the base of the round could be fed forward by the stripper rail.

    By chuck on Jun 9, 2011

  20. chuck — Agreed 100%. I just lump all of that into a failure to feed.

    By ToddG on Jun 9, 2011

  21. I don’t because these have very different causes generally speaking.

    By chuck on Jun 10, 2011

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