Privacy guaranteed - Your email is not shared with anyone.

Welcome to Glock Forum at

Why should YOU join our forums?

  • Reason #1
  • Reason #2
  • Reason #3

Site Description

New here and I have a question

Discussion in 'The 10 Ring' started by 10mmau, May 12, 2012.

  1. 10mmau


    May 5, 2012

    I have been lurking here for awhile and really enjoy the forums, lot's of good information and information sharing.

    Anyway, I have a G20sf Gen 3, stock in all aspects, and have about 400 rounds through it (a mixture of factory and handloads) and seemed to have developed a problem at this point. Specifcally a FTE. (read extract) It appears after firing that the brass is extracting only about 3/4's of the way out of the chamber. I originally believed the problem was due to an excessively dirty chamber caused by unburned powder particles and residue(14.0 grains AA#9 under a 180 XTP & 14.0 grains AA#7 under a 155 XTP) however after repeated cleaning and firing the problem persisted even with AE factory ammo. I detail stripped the gun and everything including the extractor looks good to go, except the loading block as shown below. It appears to me that the loading block itself is not sitting flush on the frame with forward portion raised ever so slightly. I cannot get it to sit flush after repeated attempts, although admittedly i dont know if it is even supposed to.

    My question is- is the loading block supposed to be perfectly flush with the frame and if it isn't could this be slowing down the slide and causing this issue? There are wear marks on top of the loading block on both sides

    Attached Files:

  2. _The_Shadow

    _The_Shadow Ret. Fireman

    Jul 23, 2007
    Southeast, LoUiSiAna
    Last edited: May 12, 2012

  3. 10mmau


    May 5, 2012

    I take it that the "locking block" is supposed to be flush unlike mine, is this correct?

    (not quite sure where i came up with "loading block" but at least i used it consistently) :embarassed:
  4. WeeWilly


    Nov 12, 2011
    I looked at both my G21SF and G20SF and the locking blocks sit down flush with the frame. Clearly your slide is dragging on the locking block in your picture. I agree with The Shadow, give Glock a call.
  5. Yondering


    Dec 3, 2011
    Just looked at my G21SF frame, the block does not sit flush, it looks like yours and has similar wear marks. Function is 100%. I doubt the locking block is the issue. Is the slide difficult to cycle by hand?

    I'd suspect a bad extractor, extractor spring, or the "spring loaded bearing" thing on the end of the extractor spring, or just a bunch of fouling under the extractor.
  6. 10mmau


    May 5, 2012

    The slide seems to cycle fine by hand and a loaded round positioned under the extractor seems to hold the round just fine. (compared to a 1911 .45 extractor)

    While rechecking the above I noticed a wear mark on the trigger bar from the slide. I do not know if this is normal or not but it could be potentially slowing the slide. (pics below) I just really think the slide speed is slow as I have seen no mashed cases where there was an attempt to rechamber the empty case.

    I think another trip to the range is in order with various ammo and myself paying much closer attention to exactly what relationship the case and extractor are in when this occurs.

    Thank you all for your responses.

    Attached Files:

  7. gofastman


    Jan 29, 2010
    Its not.

    Welcome and good luck!
  8. blastfact


    Aug 15, 2011
    My G20 has the same wear marks. My locking block does stick up a tad on the front. But only half as much as yours.

    Check the surfaces on the inside of your slide. If it's really binding up you will see matching wear marks on the inside of the slide. My slide shows no wear marks. This leads me to believe the wear marks are the result of frame flex be it the locking block or trigger transfer bar.
  9. bac1023


    Sep 26, 2004

    Hope you get it worked out
  10. Cwlongshot


    May 31, 2011
    Personally I would look at the extractor and its spring... A worn extractor or one that was ground wrong as well as a wrong tensioned spring could cause this issue. If its a newer gun simply return it to Glock and have zero worries... Welcome and good luck, CW
  11. Taterhead

    Taterhead Counting Beans

    Dec 13, 2008
    Boise, Idaho
    Welcome to the 10 Ring 10mmau.

    Yes, it seems clear that something is binding up when under a load if it is hand cycling ok. The locking block in my Gen 3 G20 sits nearly flush. I have similar wear marks, but mine has quite a few thousand rounds through it.

    If it originally cycled ok and the problem is relatively new, then something bent or became misaligned. I had an extractor not too long ago that worked its way to the left (when looking down from the top so that it was just missing or barely catching the extracting brass.

    Quick note: 14.0 grains of A7 under a 155 XTP is a very hot load. Accurate's max is 12.7 grains at a listed 37,500 psi.

    I would follow the advice of those who suggest contacting Glock. Of course shooting reloads is supposed to void the warranty. So...

    Keep us posted. I am curious to learn how this worked out.
  12. TDC20


    Apr 11, 2011
    My G20 locking block is also canted a little like yours (not flush with the frame) but not quite as much as yours. Mine has close to 2000 rds and doesn't have wear marks like that on it. What kind of lubrication are you using? I use Remington Universal grease on the slide, applied sparingly with a toothpick on the wear points and liberally on the slide groove. I do this with all my semi-auto pistols and haven't had any problem with reliability, even in extreme cold weather. I would suggest using some type of grease that doesn't fly off after 10 or so rounds like oil does, even something like wheel bearing grease would be a good option. I clean off the grease after about 200rds and replace it, since grease (and oil) collects contaminates that will actually increase wear on the contact surfaces once it gets dirty. I've had this jar of Remington grease for almost 20 years now and still haven't used a quarter of it yet. :whistling:

    I agree at this point that contacting Glock is probably your best option. Unfortunately, not all Glock factory parts are first-run quality (see my avatar photo), but the design itself is truly a great design. Once you get the problem ironed out, I'm sure your pistol will be a great performer, like mine now is. Good luck!
  13. dm1906

    dm1906 Retired SO

    Sep 7, 2010
    PRK (Kalifornia)
    I have a G20 (Gen3, purchased new) I've been shooting for a few years, and several thousand rounds (about 1/2 of them "nukes", by some standards, and most of the rest just "full power"). The lock block is firmly flush with the frame and solid. I'd post a pic, but it's so "textbook", it wouldn't show anything of interest. If it became loose, or departed from the frame, in any way noticeable, I'd be concerned. While I wouldn't consider it catastrophic if it did, it would effect timing with some rounds, barrels or combinations, and could cause some harsh firings. Glock should take interest in this, and make repairs as necessary. And, yes.... Remanufactured/reloaded rounds may be an issue, and will only cost you more in the end if they know or suspect their use. Parts are relatively inexpensive, and Glock is fairly forgiving, if it comes to that.
  14. nickE10mm

    nickE10mm F.S.F.O.S.

    Apr 13, 2004
    Wichita, KS

    As Shadow said, contact Glock asap and they will sort it out for you.
  15. 10mmau


    May 5, 2012
    Thank you for all the replies. Been out of town for a few days and hope to get out today and take one more stab at self diagnosing before having to contact Glock. For those of you interested I will update with new info when available.
  16. 10mmau


    May 5, 2012

    Well I was finally able to get out and shoot the G20 again.(no small feat I might add) I fired 1 box of AE 180 FMJ, 1 box of my hand loaded 155 XTP/AA #7 & and 1 box of my hand loaded 180 XTP/AA #9. 150 rounds and not a single hiccup of any kind. I must admit that I am perplexed. (and happy) I think at this point I will load up a couple hundred more and see what happens.