34 MOS taking a beating

Discussion in 'Sights, Optics and Lasers/Lights' started by RPMSTL, Feb 2, 2017.

  1. RPMSTL

    RPMSTL

    Messages:
    784
    Likes Received:
    791
    Joined:
    Apr 7, 2015
    My 34 MOS with Burris Fastfire 3 is taking a beating.

    Even though I have been heavily running the 34 since July '16, I just recently noticed how beat up the dot's frame is getting from the ejected shells. I don't count rounds, but it is in the several thousand range. My dot has started to turn itself off during shooting and this led me to a close inspection. That's when I noticed the raw aluminum showing through. I do not know if the beating from the ejected shells has any bearing on the dot starting to malfunction. Burris is getting the dot sent back to them soon, as they have a great warranty and have already said to send it in.

    I wrongly assumed that my Gen 4 34 is not experiencing brass to face (like my 19.4) but it seems that the dot was just masking the issue. While watching a friend pull the trigger I could see exactly what was happening.

    The spent shells come up more than out of the top of the ejection port and get slammed by the dot on its return to battery. A vast majority of the casings hit the dot. Some even hit hard enough to get thrown forward. The casings need to eject quickly to the right to avoid contact with anything mounted to the top of the slide.

    I will be detailing my future attempts at getting this fine weapon to eject properly.
    I have lots of different Glocks and parts - both aftermarket and factory issued. I will try all popular ideas, products and repair theories and hopefully come up with a solution that will help others.

    I have already dealt with this issue on my 19.4. The combo of a 15 lb spring, Apex Gen4 Extractor & supplied spring, along with the non-loaded chamber indicator bearing has proven to produce a strong and consistent ejection. We will see if these same parts (different spring of course) produce similar results on a different gun.

    I am going to try other ideas such as .40 cal components from a G22.4 to see what happens.

    So far I have tried replacing the RSA with a 15lb ISMI spring setup from NDZ Performance with no positive results - as far as ejection pattern. The spring rate reduction did have a nice feel to it. Possibly a placebo effect, but it sure seemed smoother and easier to keep the target ( 8" steel at approx. 20 yards) in the dot's window throughout the recoil and return to battery.

    Hopefully can get back to the range soon with a camera, helper and bag of parts to get to the bottom of this issue. It's odd that lots of shooters try lots of fixes for this all too common problem and everyone reports different results.
     
    Buckshot Barry likes this.
  2. RPMSTL

    RPMSTL

    Messages:
    784
    Likes Received:
    791
    Joined:
    Apr 7, 2015

  3. RonS

    RonS Millennium Member

    Messages:
    15,413
    Likes Received:
    6,154
    Joined:
    May 27, 1999
    Location:
    Oh, USA
    Glock needs to fix their ejection issues. There is no excuse for a design that is so poor that there is that much individual variation between instances of a product.
     
    BigMoneyGrip likes this.
  4. Joebiker

    Joebiker

    Messages:
    319
    Likes Received:
    386
    Joined:
    Dec 25, 2016
    I had a gen3 19 that was acting up. I stoned the top and bottom of the extractor, fixed it.
     
  5. MoRivera

    MoRivera

    Messages:
    1,966
    Likes Received:
    872
    Joined:
    Jun 21, 2015
    I have a 34 MOS as well and the brass comes out rather weakly and straight back. Is it an ejector, exctractor, or recoil spring issue?
     
  6. RPMSTL

    RPMSTL

    Messages:
    784
    Likes Received:
    791
    Joined:
    Apr 7, 2015
    We're going to find out.
     
  7. RPMSTL

    RPMSTL

    Messages:
    784
    Likes Received:
    791
    Joined:
    Apr 7, 2015
    IMG_2398.JPG

    Hard to get a good pic, factory plunger is delaminating.
     
  8. Buckshot Barry

    Buckshot Barry

    Messages:
    2,497
    Likes Received:
    1,420
    Joined:
    Jul 19, 2004
    Location:
    24 miles from the Mothership
    FWIW, I just tried the spring load bearing from my G27 without LCI in my Gen 4 34 and it had no bearing on the case ejection.

    My 34 is mostly stock, except for a 13 lb ISMI spring, Jager poly rod, and 5 lb Wolff striker spring. I am please with the ejection I get with wimpy Walmart Federal Champion 115's. I was just seeing if it would be even better with the slightly longer non LCI spring load bearing.

    Your ISMI spring is what caught my eye and prompted my reply.
     
  9. bac1023

    bac1023

    Messages:
    125,037
    Likes Received:
    26,891
    Joined:
    Sep 26, 2004
    Location:
    PA
    I agree. It's been an issue for years now.
     
  10. intenseneal

    intenseneal

    Messages:
    593
    Likes Received:
    154
    Joined:
    Jan 10, 2013
    Man sucks, sorry to here and hope you fix it. Have you tried different loads or does it do this with all types and brands of ammo? I hear online a lot about glock ejection issues. Personally my gen 2 G23 ejects at 3-4 oclock, even when it had a broken ejector and every glock I have shot has had no ejection issues.
     
  11. 9x45

    9x45 Millennium Member

    Messages:
    6,902
    Likes Received:
    4,662
    Joined:
    Jan 31, 1999
    Location:
    Southern California
    Yup, the newer Gen 3's seem to have that issue. The fix is an Apex extractor.

     
    Buckshot Barry likes this.