Sidearms & Scatterguns Glock experts?? Need advice on G4 34

nfoley

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So I bought a gen 4 34 and had the slide milled and put a RDS on it. Getting problem seen in the pic - failure to feed with the round jamming hard against the bottom of the feed ramp. Factory 115s, tried different mags.
Any of you Glock guys see this before and have advice? Thanks!
53B18E47-3A27-488C-BBAA-D017F6056722.jpeg
 

Old Man with Gun

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Have you tried different types of ammo? Some full power loads to be sure the slide is getting full battery. Especially a new gun may have a break in period, my first guess is slide is not going all the way back firmly.

Try a very firm grip as well.
 
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mcameron

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    any other mods to it?

    mag release?
    magwel?
    barrel?
    recoil spring?

    what brand of ammo? have you tried another type of ammo?
     

    Hoyter87

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    You need a heavier weight recoil spring. Between the slide cut out up front and now the milling you have removed enough weight from the slide that your factory recoil spring is not providing enough tension for proper cycling. In short, the slide cycles so fast the mag isn't lifting a round up to be grabbed in time.

    I could be completely wrong about this but I have modified a lot of Glock race guns and my experience with gutted slides is that they require more recoil spring lbs.

    The truth about Glocks is that you can swap the trigger and a drop in barrel and should leave everything else stock. They do not run well once modified.
     

    nfoley

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    It is not a new gun, and did function fine before slide work. Everything else is stock. Actually that is not true, it has an aftermarket extended mag release.
    I did try putting a 20lb spring (factory is 17) and it still did it. Seems like that should have worked. May just try a lighter spring but that goes against what seems to make sense to me.
    I did know sending out the slide might screw things so kind of got what I deserved.
    I do really like how it turned out - looks great and I’m sure with more tinkering it’ll work again.
     

    Hoyter87

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    I'm surprised the 20 lb spring didn't fix it.

    What happens if you load a single round in the chamber and fire? Does gun return to battery?

    Did they cerakote or do any coating to the slide? Is your drop in barrel super tight to slide? I'm now leaning towards the barrel not having enough tolerance to cycle due to slide work.
     

    mcameron

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    if you sling shot the slide, will it chamber?

    what if you bump the back of the slide with your palm?


    how does the slide feel when working it on the frame?....does it run smooth or does it feel like it hangs up anywhere?
     

    nfoley

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    Not sure I understand first question- if I put one round in the pistol and fire it will fire and then slide locks on empty mag.
    They did black nitride the slide but the barrel seems pretty loose in the slide. I do have another barrel (threaded barrel) that I could try and see if it does it with that. Btw, seems to happen about 1 in 50 rounds. Not frequent.
    Mcameron, if I sling shot it does load. But a couple of times the round gets so jammed against the bottom of the feed ramp that it won’t. The slide feels very smooth when just working it back and forth. Have a G19 and G17, feels just like they do.
     

    Old Man with Gun

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    Does it seem to happen when the magazine is mostly full more than almost empty? As mentioned the lightened slide may be outrunning the magazine.

    An extra strength magazine spring could help.
     
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    nfoley

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    Just the factory 115 (Norma) - they run 100% in G19 and G17.
    Milling by Hexagon Precision in Texas.
    The Red Dot screws don’t protrude.
    If actually does seem to happen more toward end of magazine. I may try heavier mag spring.
    So if lightening slide causes it to outrun the mag shouldn’t heavier recoil spring fix it?
    Maybe I will try 22lb spring.

    I am enjoying shooting it so don’t mind all the experimenting!
     

    Hoyter87

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    What is the power factor of those Norma 115s? If they're particularly hot they might not cycle at 20 lbs if the slide is light enough.

    Try upping it to a 22lb spring.
    If you're still having issues after 22 lb spring then you have a few options:

    At one in fifty frequency of issue I'd probably just shoot the gun a bunch and see if it sorts it's self out with wear and break in.
    I have also read that new aftermarket barrels require about 100 rounds to really fit the gun properly. I have never personally experienced this.

    If it doesn't then consider going back to stock spring and pursuing polishing around where barrel locks up into slide and your feed ramp then start over on spring process.
     

    nfoley

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    Thanks Hoyter, appreciate the suggestions.
    Will try those things. I will run some rounds thru chrono to check PF.
    Will report back so everyone can know the outcome.
     

    Sogan

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    Always run a gun for awhile before paying a ton of money on mods
     

    WB300

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    How old are the magazine springs?

    Can you tell if the follower is tilting down a little?

    Do you know if the magazines were stored fully loaded for long periods of time?
     

    nfoley

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    I did order a 13 lb spring. $8 to try it is worth it for me. I contacted Hexagon Precision and the response was “we have never had a single issue ever after milling. You’re limp wristing it.”
    Lol.
     

    nfoley

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    Just an update- put in a different (aftermarket) barrel and it ran flawlessly with both stock spring and 20lb spring and same ammo. 300 rds total on 3 different days.
    May have just needed more rounds. Will try factory barrel again now
     

    Forrest84

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    I’ve had plenty of slide milling on Glock 34/35’d and allways went lighter on recoil spring and have never had problems cycling until I went below 14#
     

    nfoley

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    The problem I had must have been related to the finish on the slide after milling. Now doesn’t matter which spring or what ammo- feeds 100%!