Glock 17 gen4 Endurance Test: Week 20

5-Aug-11 – 22:51 by ToddG

30,276 rounds 7 stoppages
(+1 w/non-LCI extractor)
0 malfunctions 0 parts breakages

Busy week with lots to report.

First, at round number 29,136 the test gun suffered another “slide over base” stoppage (hat tip to Chuck and his doesn’t-have-a-bolt Glock). Different magazine than last time (Week 11, round #16,030) and the pistol had been lubricated less than 100 rounds prior to the incident.

While it is hard to overlook any stoppage, as I said last time it’s unavoidable if you run a gun hard. Coincidentally, it happened almost exactly 13,000 rounds after the last one, which had been the first stoppage in about 13,000 rounds. So when I said during Week 11 that a Mean Rounds Between Stoppage of 13,000 was ok, I guess the gun heard me.

The pistol fired more than 1,000 subsequent rounds the same day, using the same magazines, without further incident.

The Glock also reached the 30,000 round milestone this week which means that a parts replacement maintenance and cleaning is due. Parts to be replaced will be:

  • recoil spring assembly (ver. 0-2-1)
  • slide lock spring
  • trigger return spring

Note that the slide lock spring and trigger return spring are not parts that Glock necessarily recommends replacing every 15,000 rounds. It’s something I’m doing as a preventative measure. The slide lock spring in particular is quite exciting when it breaks. If you’ve never seen a Glock slide launch off the frame and sail downrange spontaneously, you’re really missing out.

As I mentioned a few weeks ago, the Glock’s almost infinite capability for customization, personalization, and modification via aftermarket parts is both a great strength and a weakness. This week, as I put some dedicated effort into improving my press-outs, I decided to give the Grip Force Adapter another chance. The nice folks at Grip Force sent me a few modified GFAs to play with that addressed the issues I’d had that convinced me to take my original sample off the gun in the first place. There’s nothing magical about the changes they made and in fact their website highlights a number of modifications customers have made.

Much like the Glockmeister Grip Plug, at least for me this modified Grip Force Adapter is like buying skill. As much as I’d rather say I can do it all on my own, the fact is that the GFA created instant improvement. For example, after dinner tonight I went back to the range and shot the FAST three times each with and without the GFA:

  • without GFA
  1. 4.91 (-2 body): 1.58,.63/1.98/.24,.25,.23 … total time of 6.91
  2. 4.63 (-1 body): 1.69,.44/1.80/.21,.21,.20 … total time of 5.63
  3. 5.08 (clean): 1.70, .58/2.11/.24, .23, .22
  • with GFA
  1. 4.63 (clean): 1.60,.49/1.96/.22,.18,.18
  2. 4.69 (clean): 1.46,.40/2.21/.22,.20,.20
  3. 4.48 (clean): 1.54,.51/1.86/.20,.18,.18

Lest you think that’s just chance or the benefit of the non-GFA runs getting me warmed up, I shot the FAST as part of my regular practice earlier in the day (with the GFA on the gun) and turned in five sub-5 clean runs in a row:

  1. 4.58 (clean): 1.59,.45/1.94/.21,.20,.19
  2. 4.71 (clean): 1.67,.48/1.91/.23,22,.20
  3. 4.81 (clean): 1.54,.54/2.10/.22,.21,.20
  4. 4.56 (clean): 1.58,.48/1.86/.22,.21,.21
  5. 4.60 (clean): 1.48,.42/2.05/.21,.23,.21
  6. 4.38 (-1 body): 1.58,.40/1.82/.20,.20,.18 … total time of 5.38

Honestly, I don’t want to like the GFA. The gun feels better in my hands without it. But not only are my press-outs faster and more certain, even my blind splits are faster thanks to the improved leverage. Running some 5-shot speed drills I was regularly getting splits in the high teens and hit a number of 0.13’s using the GFA. Without the GFA, those numbers were all about three hundredths of a second higher. That’s the same difference you see in the averages between the with & without GFA FAST run comparison, too. Now I’m the last guy to say that three hundredths of a second on your blind splits is critical. If you can get it for just $26.95 shipped, though…

Let’s face it, you have to choose shoots better over feels nice.

One issue I had with the Grip Force Adapter the first time around was the increased reach to the magazine release. The GFA made it just far enough that I had to shift the gun considerably to drop the magazine. Now, thanks to the Mag Catch Fairy, my test gun is sporting the nifty FBI extended magazine release. Much like the FBI mag button for gen3 guns (or, as we like to call it, “the mag catch Glock stole from Larry Vickers”), the gen4 FBI button is nowhere near as obtrusive as Glock’s competition mag buttons. It’s only slightly longer…  but it’s the exact right size for my small hands, especially when the GFA is installed on my gun.

This is the best I could do on a picture comparing the two mag buttons side by side. The gun in the foreground (more to the left) has the stock gen4 mag button. The gun in the background (more to the right) has the FBI variant.


And before you ask, no, I do not know where you can find one. But you could try ripping all your teeth out and leaving them under your pillow. (disclaimer: if you rip all of your teeth out and leave them under your pillow but do not get a FBI extended gen4 magazine release from the Mag Catch Fairy, that’s your problem)

Finally, this week the G17 turned in what will absolutely go down in history as the all time record setting run on the so-called “Humbler” 700 Point Aggregate course for fire. Because out of 700 possible points, I scored 715. Cold. No warm up. Just me and the Glock 17 versus, um, math.

Now, I’ll explain how, but it’s going to make that incredible score seem a lot less spectacular and impressive. So first, just sit there for a minute and bask in the awesomeness of scoring 715 out of 700.

OK, here’s what happened. I shot the drill from memory and accidentally added two 5-shot strings of fire: weak hand only timed fire (20 seconds) and weak hand only rapid fire (10 seconds). That gave me an extra eighty-five points over the 630 I actually shot. But 630 doesn’t sound nearly as impressive. Things were actually going very well up until the last five shots (five from the prone in 20 seconds) when I managed to drop eighteen points on top of the three I threw away on the prone slowfire stage.

Prone. What kind of lazy bastard lies down in the middle of a gunfight, anyway?

Train hard & stay safe! ToddG

Previous Glock 17 gen4 Endurance Test posts at

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

  2. Fun read all the way around.

    By JHC on Aug 5, 2011

  3. Todd,

    Honestly, one of the best parts of your weekly updates are the photos LOL, great work on the FAST drills, I also found I shot faster with the GFA, but I was having problems manipulating the gun during reloads and tac loads, even using the Vickers mag release.

    By shepardj on Aug 5, 2011

  4. What kind of modification was made to the adaptor? I can’t remember what issues you originally had with it.

    By Emanuel Plotnikov on Aug 5, 2011

  5. It looks like it has been shortened quite a bit from the original (it doesn’t extend as far down the back strap) and it also appears to have been smoothed just above the cut. I could be wrong though.

    By Evan_O on Aug 6, 2011

  6. And you said this would be a slow week. Great read.

    By NickA on Aug 6, 2011

  7. Todd, during my past training session I had the “slide over base” malfunction occur three or four times in my M&P 9mm. Ammo: CCI Blazer Brass. Pistol uncleaned/unlubed for around 2000 rounds (pistol and all mags now cleaned). Mags: standard 17 rounders from S&W. Assuming no underpowered ammo problem, would this be an mag spring problem?

    By Doc Todd on Aug 6, 2011

  8. Todd,

    It looks like the GFA might make it a pain to thumb the gadget. Does it?

    By Tyler on Aug 6, 2011

  9. EP — The standard GFA adds just enough width and length to the frame that my grip was compromised; I couldn’t get a 360-degree grip and still apply good lateral force on the pistol. Grip Force reduced the profile a bit while maintaining the change in grip angle, which is the biggest benefit. The beavertail also provides some leverage under recoil and is probably playing a role in helping with the blind splits.

    Doc Todd — While it could be any number of things, checking magazine spring tension would be a smart place to start.

    Tyler — Good observation. Yes, it makes it a little less intuitive to get thumb on gadget. But it’s just a matter of turning practice into habit. After one long day on the range, I don’t even think about it anymore. My thumb contacts the correct spot on the back of the gadget and everything works.

    By ToddG on Aug 6, 2011

  10. Is your typical tap-rack-bang sufficient to clear a “slide over base” stoppage, or would you have to clear it like a double feed?

    By Chance on Aug 6, 2011

  11. Todd, is the FBI ext. mag release polymer or alum. I’ve seen these made out of aluminum but, not sure how that would wear on the polymer magazines.

    By BWW on Aug 6, 2011

  12. So when is the gadget going to be made available or is it already?

    By Emanuel Plotnikov on Aug 6, 2011

  13. Chance — No, like most out of battery stoppages a tap-rack won’t solve it.

    BWW — The FBI mag release is polymer, just like all the mag releases that Glock puts on its guns.

    EP — We’re still in the testing phase for the Gadget. No specific timeline for when it will go into serial production.

    By ToddG on Aug 7, 2011

  14. Chance,

    In many weapons, and most of my experience is with the M16 FOW ref bolt-over-base malfs, you need to strip the mag and get rid of the non-feeding round since the bolt has made contact with and most of the time damaged the middle of the case. That round is also typically stuck all catywampus in the feed lips.
    I’ve never had a “bolt-over-base” with a Glock but I have with several other pistols and found things to be pretty similar.

    By Chuck on Aug 7, 2011

  15. BTW, this is almost always a magazine issue. With M16/AR15 mags, especially the old 20 rounders, the issue was often weak springs, and the follower design kind of sucked.

    In this case it could be the mag spring getting weak, could be some small obstruction like powder flakes making the follower stick.

    By Chuck on Aug 7, 2011

  16. I modded my own extended mag catch out of an aftermarket part I picked up from Their part was wayyy too big, so I filed on it a bit.

    What I came up with looks a lot like the FBI button except for the serrations, which I couldn’t replicate with my soldering iron. 😉 I’ve been running it since mid-June, and I’m loving it. Word is that Tango Down is working on bringing out a Vickers Gen4 extended catch.

    Follow this link to a GlockTalk thread with some pics of my mag button:

    By sgtlmj on Aug 8, 2011

  17. Does anyone know the Glock Part Number for the Gen4 FBI Mag Release?

    By paul on Aug 21, 2011

  18. I too have begun using the GFA on my 3rd gen Glocks. On the G17, I just reduce the ridges on the underside of the beavertail. With the G19, I do the same ridge reduction, but also cut the grip portion in half, much like the one on Todd’s pistol. I also stipple the GFA on 3rd gen Glocks that have been stippled. On RTF2 pistols, the GFA’s built in texture works fine.

    By DocGKR on Sep 2, 2011

Sorry, comments for this entry are closed at this time.