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Glock Hunt: Ambidextrous 21 SF

Discussion in 'General Glocking' started by WillTheBeast, Sep 8, 2012.

  1. WillTheBeast


    Sep 3, 2012
    Hello all,

    This will be my very first post on the Glocktalk forums, although I have been a "lurker" here for some time.

    My issue: For the last 2 months I have been attempting to hunt down a Glock 21 SF with ambidextrous magazine release and picatinny rail. I have been mostly unsuccessful at finding one. The ones that I do find are often from individual sellers who are not willing to ship out of state. And as my luck would have it, my local gun shop actually has one! But the poor thing is beat to hell. Go figure... :burn:

    So now I will enlist the help of the wonderful GT community in my search. If any of you know of, or currently have a 21 SF w/ ambi mag release and pic rail up for sale I would appreciate it if you would let me know!

    And before anyone mentions it. Yes, I am aware of the problems with the Gen 3 ambi magazine release. I tend to be the type to make small modifications/fixes to any issues with my guns, so I will likely be modifying the mag release to increase its durability/reliability. I plan to add a fluoropolymer coating of some sort to increase the wear/abrasion resistance of the polymer parts, making the mag release both smoother and more durable (less likely to stick). Hopefully it will work. If anyone knows of a different fix please post it here.

    One last thing, since the picatinny rail model is considered to be rare I am curious to know exactly how uncommon they really are. If anyone has information on approximately how many of these models were produced I would be interested in knowing.

  2. ghostrider88


    Feb 13, 2009
    The 21sf ambi discontinued "PROBLEM CHILD" Check out the Gen4 with reverseable mag release :cool: a lot people sent their frames back to glock to be replaced with Gen3 glock rail,standard mag release.
    Last edited: Sep 8, 2012

  3. lyodbraun


    Jan 3, 2012
    NW Ohio
    I saw one last week on Armslist in the Ohio section, you will prob have to do some digging back through them but there was one for sale... good luck..
  4. I just sent my primo example back to the mother ship for replacement the other day, wish I would have met you sooner.

    Welcome to GT!
  5. WillTheBeast


    Sep 3, 2012
    Funny that you mention that. He was one of the gentlemen who would not deal out of state lol.

    I am aware that the Gen 4 is "ambidextrous" in that you can switch the mag release from one side to the other. I am more interested in the Gen 3 because it is the only truly ambidextrous that Glock has produced. And I think the Gen 3 platform is slightly more reliable than the Gen 4 anyways :whistling:

    Last edited: Sep 8, 2012
  6. FFR Spyder GT

    FFR Spyder GT Ex-Gunslinger

    Apr 27, 2012
    Hog Jaw, Arkansas
    I just checked my Glocks and I have an unfired NIB G21SF w/ Picatinny rail and ambi mag release.

    One day I might get around to shooting it.
  7. AK47Man

    AK47Man Expert Marksman

    Feb 7, 2007
    I have a Gen 3 21SF Ambi with rail with everything you were looking for...BUT...It is NOT for sale...One of my best shooters without any problems...What type of problems was this gun having Ghostrider88?
  8. WillTheBeast


    Sep 3, 2012
    No worries, it seems that Craigaz is going to hook me up :cool:

    The Gen 3 ambidextrous mag release has been known to get stuck depressed to one side or the other, which will not allow the magazine to seat properly. In more uncommon cases (usually after the sticking problem has arisen) the pieces of the mag release will fall completely out of the magwell, along with the magazine.

    Some people have had these problems with the ambi 21SF right out of the box, but others have put thousands of rounds through theirs with no problems at all. So it is still a bit of a mystery as to why exactly the release will sometimes fail or come apart.


    Nov 5, 2001
    North Carolina
    Same as the above poster. Mine was a pristine example however very dirty. Sent back to Glock and it was returned in the form of a brand new blue label G30 Gen4 with 3 new mags.

    Sorry man.
  10. seaswol

    seaswol NRA Life Member

    Sep 10, 2006
    Red Neck Riviera
    I have a never fired blue label, G21SF ambi. I would be pleased to get a Gen3/4 G30 or G20. Do I need to drive up to Atlanta from Pensacola?? My wife would love a "shopping trip" to Atlanta.
  11. Wizard9


    Sep 29, 2012
    What are you looking to pay for a like new, less than 2k rounds run through it, original owner?
  12. faawrenchbndr

    faawrenchbndr DirtyThirty fan CLM

    Nov 24, 2005
    Good luck with that Will!
    Glock could not fix it, the created FAIL & failed to fix it.
    No way to redesign it, but knock yourself out!
    Try to locate a Police Supply Distributor, best chance at finding a NIB one.
  13. Shinytop


    Sep 5, 2012
    Man, too bad you are not interested in a G22. I just fired a 21 over in Daphne and will be looking for a 21SF or 30SF. My 22 has 700 rounds through it and I have 300 rounds on hand.

    Oh, and I am in Pensacola.
  14. WillTheBeast


    Sep 3, 2012
    Thank you for the offers gentlemen. I actually have my ambi 21 now, so unless I decide that I need 2 I am all set :supergrin:

    [Long post incoming]

    I have taken apart the ambidextrous mag release to see what all the fuss is about. I have to say, it is pretty simple in terms of function, but it is very difficult to get back together after dismantling it (especially if you have big fingers). It looks to me like the main issue with the ambi mag release "sticking" comes from the thin metal bar piece that provides the tension for the button to return to center after being depressed. I put it back together in what looked like the right way... and yet it began to stick each time I pressed it (on both sides) It turns out that if the metal piece is not seated 100% down into the slot in the frame, it will not rest all the way against the tilting metal tab that holds/releases the magazine and will then get trapped against the front of the magazine when the button is depressed. So the "sticking" that everyone talks about is actually the thin metal tension piece becoming trapped between the release and the magazine. After I pressed the tension piece more firmly into the frame and tried again I got it to contact the tilting metal tab properly, it seems that the tension piece has has a small bump near the top that fits under the ledge at the bottom of the rotating piece, this will allow it to lean further towards the front of the frame by about a milimeter and thus not come into contact with the magazine.

    So not to say that I have solved all Gen 3 ambidextrous mag release problems... :whistling: But I am fairly confident that the same fix would solve the problem on a different gun. My Glock 21 was nearly new and showed no problems before I started to mess with it. I think that because I was able to replicate the problem that everyone has been having (short of the pieces falling out of the frame) that the ambi mag release doesn't actually "break" but can become improperly seated in the frame, causing the metal tension piece to jump off of its little bump and then become trapped against the magazine, then you have a mag release failure/sticking problem.

    As for the parts falling all the way out of the magwell as some have experienced, I believe this is due to the parts (just the same as above) becoming loose, but unlike in my instance where the tension piece was only slightly out of its slot, if the tension piece is even further out of its seating I think it would be possible for the next magazine that is inserted to grab or catch on to that tension piece and pop it all the way up out of the slot in the frame. This would allow it and also the tilting plate thingy (which would now be 100% loose) to fall free of the magwell along with the magazine.

    So there you have it, that is my theory on why the ambidextrous mag release fails. If any of you have one that has failed or is giving you trouble I would encourage you to try and get the tension bar piece seated more firmly into the frame so that it rests against the tilt plate properly. If that doesn't fix it then I don't know what will.

    Also, since this is not really a permanent fix and the same problem could probably present itself again. It might be a good idea to put a small drop of superglue or locktite down in the metal tension bar's slot, to prevent it from working its way up out of the frame.

    If there are any Glock armorers/experts out there I would like any feedback you could give. I think I am on the right track here but would appreciate some "peer review."

    Thanks all,
  15. NH Trucker

    NH Trucker Needs coffee...

    May 4, 2009
    Concord, NH
    Great post Will, and congrats! I also had issues with mine dumping its parts, but I did some trouble shooting and managed to find what I believe was the problem, as well as what seems to be a permanent solution to that problem.

    The problem with the 21sf ambi mag release was when trying to eject a full magazine, extra force seemed to be needed to fully depress the release button. This extra force would cause the internals of the release mechanism to shift in the direction of the force, resulting in the flat spring that holds it all together to walk out of its slot. Once it comes out of its slot enough, all of the pieces just fall out of the gun. That was the issue I had with mine, which in an effort to find a fix is what caused me to stumble across GlockTalk in the first place. I never was able to find an answer to the problem on the site, so I ended up trouble shooting it and figured out the problem on my own, as well as coming up with a fix.

    The cause of the issue is the design of the magazine catch. The edge where it makes contact in the groove on the front of the magazine body is squared. When trying to eject a full magazine, the catch moves upward and in, which in turn tries to force the magazine in an upward direction. The excess force needed on the release button is because this upward movement of the magazine works against the upward force of the magazine spring. Doing this with a magazine carried -1 (12 in mag after chambering 13th round and not topping it off) makes it so that there is little effort required, as there is some spring compression still left available. But with the magazine fully loaded with 13 rounds, the mag spring is fully compressed, and with it unable to compress any more, the magazine will not move upward without significant force, either on the release button or with your support hand pressing up on the floor plate of the magazine.

    HOWEVER, the modification I suggested to the magazine catch is an easy one. The 90 degree corner where it makes contact with the notch in the mag body: GENTLY round that edge. You're not looking to remove a lot of material, just make the corner a little less sharp. This will provide less resistance to the catch in this notch, and the VERY LITTLE material removed will result in a slight increase in tolerances making it so it isn't pushing the magazine up as much. It does not however remove enough material to effect how the magazine is seated or how securely it's seated. When putting the mag release back together, make sure the flat spring is fully seated in its groove.

    That is the modification I made to my G21sf, and thousands of rounds, hundreds of magazine changes, and plenty of ejections of full magazines later, I have yet to have another problem with it, and I trust it as my daily carry.
  16. WillTheBeast


    Sep 3, 2012
    Thank you Trucker,

    I was able to get the mag release to stick again on one side due to the force problem you described, I hadn't been dropping full mags before. It does look like friction from side to side is the main problem, which would walk the flat spring out.

    It looks like rounding that edge as you suggest and also keeping the flat spring fully seated down in the frame should make the ambidextrous release as reliable as Glock intended it to be :cool:
  17. NH Trucker

    NH Trucker Needs coffee...

    May 4, 2009
    Concord, NH
    Too bad no one at Glock decided it was worth the effort to figure it out and fix it. Everyone I read on here who were having that problem sent theirs back to Glock and got replacement frames that were just the standard release. Too bad, because I like having that feature.

    Once I rounded that edge on the mag catch, I never had another issue with the spring coming up out of its slot. I think that fixed the issue. I also haven't had an issue with the release button sticking since then either, and I made that fix 3 1/2 years ago.
    Last edited: Oct 6, 2012
  18. vegetius

    vegetius vegetius

    Sep 27, 2012
    Have Gen 2 Frames ... with built in CT laser modules as part of the modified trigger guard ... bought Gen 3 Frame to use CT Green Laser Rail Module ... going to use Gen 2 frame in a Mech Tech Upper ... have 17 KCI 28 round G21 mags (loaded to 25 rounds) ... with collapsable wire stock ... nice .45 ACP Carbine ...

    Have 20 to 30 mags I picked up over the years ... only 5 will seat in the Gen 3 Frame with the TAC Rail and my green laser ... Bummer ... the 28 rounders will seat but hard to conceal ... you think?

    Will Glock take my Gen 2 Mags in on trade for Gen 3 Mags? Stupid question but had to ask ...

    Am I screwed? more stupid quetion asking ...

    Any suggestions would be appreciated and all criticisms accepted with proper attitude

  19. DFin


    Mar 22, 2008
    If you push up on the bottom of a fully loaded G-21 mag before you depress the mag release it is much easier to release the mag. This method does not put the pressure on the ambi mag release that may cause it to malfunction. Also, if it is working ok, don't touch the flat mag release spring. The one time I had problems with one of my Picrail G-21's was when I decided to touch the flat spring to put a dab of oil on it. I obviously moved the spring up a little and out of its' slot.

    I am reluctant to trade mine in because I like the look of the picrail. Mine are also reliable and I don't want the risk of getting unreliable pistols from Glock.
    Last edited: Feb 10, 2013