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G21/Gen 4 Failure to feed issues

  1. I purchased a G21 Gen 4 last September. I took it to the range and ran about 2000 rounds of ball without a hiccup. Every January, I cycle all my duty ammo and get new stuff (I have several other guns that have duty ammo). My G21 ran steel, aluminum and brass ammo but I got failure to feed (FTF) from my Hornady Critical Duty, Federal HSTs, Winchester PDX1's. Every other round nose dived in my magazines or caught under the ramp of the barrel. I took it to my gunsmith and he polished the ramp. I still have FTF's, just not as many. My G21 does well with Federal HSTs, Remington Golden Sabers and Speer Gold Dots at the moment. I have no luck with my Hornady Critical Duty. I won't carry my G21 in public (as I'm not confident I won't have a FTF at the wrong moment). I'm still researching the possible causes. I've got five Glock OEM 13 round magazines (no modifications). Any thoughts? Thank you in advance.
  2. Polishing a feed ramp will not help a nose down in the mag
    problem, the round has not got to the feed ramp yet.

    I have that problem with the more powerful loads too and
    other jams also with most Glocks I have owned.

    I think there is too much slide speed and the mag spring
    can't keep up, holding the gun very tight with a very stiff
    arm I believe also causes that.

    It makes the slide run faster and more violent.

    Things that can usually help in combination or by itself,

    stronger RSA,
    adding weight or a comp to slide and or barrel,
    stronger magazine spring,
    not holding the gun too tight and with a stiff arm.

    With an auto pistol it's a balancing act, you have
    to keep the ammo within the design limits of the
    gun or change the limits of it's design for different
    loads, be they weaker or stronger loads.
  3. Thank you for that. I'll have to go back to the drawing board for a solution. I was contemplating changing guide rods (others were suggesting the same thing). At the moment, I'm using standard pressure loads (230 gr) until I can get this solved. I don't have to use +P ammo, but I'd like to have the option. This gives me something else to think about. Thank you Happie!
  4. I understand your problem, have been playing with
    Glocks in different calibers including the 460 Rowland.

    I hate comps and the extra noise they divert back to
    the shooter so I am still playing with it to find a good

    A comp really does work though.
  5. My G21 has a Recoil Rebound guide rod. It's adjustable but I'm unsure how to adjust it. I'm in the process of getting with the company for technical advice on how to use their product effectively. I still have my factory guide rod and I'll switch to that until I've found a viable solution.
    I've tried to stay with two calibers over the last few years (9mm & .45) but I'm going to venture out into the .40 S&W realm in the next couple of months. I'm going to get the G27 and the G23. I like the idea of using conversion barrels to change the calibers.
    Getting back to my G21, once I iron that issue out, I'll be at peace with it. I love Glocks and Springfields (XD Mod 2's).

  6. I have many conversion barrels for Glocks,
    that is why I went with Glocks in the first place.

    See these links, have done most of what
    is in them and more.



    I had three G30 Glocks, down to one gen 4 now, will
    keep it.

    Have a G21 and will probably get one more, have shot
    9mm, 357sig, 40s&w, 10mm, 45 acp, 45 super and
    460 Rowland in it. Most of my barrels are six inch
    or longer for it.

    It is the most versatile gun Glock makes and I always
    like to have one with the barrels handy, always take
    it on trips.

    I also have a gen 3 SS LW slide in 45 for the G20.

    Will probably sell it because I don't have a gen 3
    G20 anymore. I do have a gen 4 G20 though and
    will probably keep it, maybe not.
  7. I am so looking forward to these next purchases. Thank you for your responses. They were very helpful.
  8. Update:
    I changed the guide rod and my problem went away. I spent a couple of hours at the range and shot almost 500 rounds (400 being hollow-point duty ammo) without a hiccup. Thank you for that advice. You were right. My G21 is back in my line up and I couldn't be happier.