AR-9 jamming rounds

The #1 community for Gun Owners in Indiana

Member Benefits:

  • Fewer Ads!
  • Discuss all aspects of firearm ownership
  • Discuss anti-gun legislation
  • Buy, sell, and trade in the classified section
  • Chat with Local gun shops, ranges, trainers & other businesses
  • Discover free outdoor shooting areas
  • View up to date on firearm-related events
  • Share photos & video with other members
  • ...and so much more!
  • ACC

    Master
    Site Supporter
    Rating - 100%
    133   0   1
    Mar 7, 2012
    2,042
    113
    N. Side of Indy
    I recently built an AR-9 using a QC 10 Glock 9mm lower and a Ballistic Advantage 5.5" 9mm barrel. Took it to the range today and it was jamming rounds. Not double feeding, but actually jamming the 9mm round up against the feed ramps and getting caught before going into battery. Pulled out the rounds and this is what I see:



    SO...do I just need to polish the feed ramp? Is my buffer spring too strong? Looking for insight.
     

    bigman502

    Plinker
    Rating - 75%
    2   1   1
    Feb 27, 2010
    65
    6
    Jeffersonville
    Are those reloads?
    If so they appear to have the bullet seated way too deep inside the case
    Get a caliper and make sure you have a correct OAL (overall length)for you 9mm reloads
    It makes a big difference in feeding issues
     

    stony

    Sharpshooter
    Rating - 100%
    9   0   0
    Apr 4, 2009
    505
    18
    Pittsboro,IN
    Are those reloads?
    If so they appear to have the bullet seated way too deep inside the case
    Get a caliper and make sure you have a correct OAL (overall length)for you 9mm reloads
    It makes a big difference in feeding issues


    I believe that is the result of the jam, or at least I hope it is.
     

    Nacelle

    Marksman
    Rating - 0%
    0   0   0
    Jun 1, 2015
    250
    18
    Muncie
    I wouldn't put a lighter spring in. You need a heavy spring to keep the bolt from slamming back so hard. I had jams on mine, not quit as bad as this. Though mine is the Colt mag version. I went home, cleaned it real good, and oiled it liberally. The next time, I only had one jam. The time after that, none. Maybe it needs to break in a bit. I'm up to about 800 rounds.
     

    ROLEXrifleman

    Master
    Rating - 100%
    54   0   0
    Feb 7, 2009
    1,767
    84
    NW Indiana
    The barrel you are using was designed for Colt pattern guns. They are not designed to be fed from a glock magazine. the angle and height is different.

    QC10 knows this about their lowers and because of that make barrels cut specifically for them.

    Here's a blurb from their web page along with the link.

    We also have designed our barrels around our Glock platforms. Most pistol caliber AR15 barrels are not made for glock magazines. They were designed around a straight style magazine. We have a different chambering contour that allows reliable feeding from glock magazines. It is absolutely recommended to use our barrels with our builds. We cannot guarentee our products to work with other manufactuers barrels who do not have hands on experience with our products. Other companies may sell a 9mm barrel but that does not mean it was made with intent to be fired with our lowers. We stand by and guarentee our products to function with each other.

    http://www.quartercircle10.com/our-products/


    Also, heres a good read on that exact issue. It's an oldie but goodie

    https://www.ar15.com/archive/topic.html?b=3&f=15&t=674866
     
    Last edited:

    ACC

    Master
    Site Supporter
    Rating - 100%
    133   0   1
    Mar 7, 2012
    2,042
    113
    N. Side of Indy
    The barrel specifically says it works with glock pattern lowers. I don't think I have a 'wrong' barrel.

    The bullets are not reloads. The picture shows one in chamberd round in the middle and all the jammed rounds around it.
     

    ROLEXrifleman

    Master
    Rating - 100%
    54   0   0
    Feb 7, 2009
    1,767
    84
    NW Indiana
    And all glock pattern lowers are not the same. Not all the lowers present the magazine to the barrel at the same angle. In your case the lower appears to have the magazine angled in a manner that the round is catching the chamber at the tip. by the time the weight and speed of the bolt close on it you get the effect pictured above. So you have one of two options...

    1) Change the angle that the magazine is presented to the barrel. The only way to do that is by getting a different lower.

    Or

    2) Get a barrel with a "feed ramp" that begins to accept the bullet sooner. One that has a different profile feed ramp than the one you have.

    Does this mean people don't get lucky and have their barrel work with QC10 lowers. No, you have functioning guns like this all the time. What it does allow for is QC10 to say if you don't use our barrel we cant guarantee a damn thing and leaves with with an unreliable gun and limited options.

    I hate to be the bearer of bad news but these are your options. Welcome to the world of the AR15 pattern rifle.
     
    Last edited:

    Dog1

    Master
    Rating - 100%
    35   0   0
    Feb 15, 2010
    2,658
    113
    Clark County, Indiana
    Are you dingleberries that are saying the rounds look too short even attempting to read the OP?

    The rounds posted are the result of the rounds jamming into the feedramp, thus causing the bullet to be pushed back in the case.
     

    Nicu757

    Marksman
    Site Supporter
    Rating - 100%
    12   0   0
    Sep 2, 2013
    239
    28
    Brownsburg
    I have the same issue to the T using all sorts of different Ammo. A QC10 lower and a ballistic advantage barrel. has anyone else had this issue? I guess I will buy a QC10 barrel and see if that changes it if so I'll need a refund on the BA barrel.
     

    Nicu757

    Marksman
    Site Supporter
    Rating - 100%
    12   0   0
    Sep 2, 2013
    239
    28
    Brownsburg
    Don't know if differt just know it does not feed right. When it did work man it was dead on but I tried 5 different mags (glock and ETS) and 3 different kinds of factory Ammo. It would not even chamber a hollow point at all.
     

    AllenM

    Diamond Collision Inc. Avon.
    Industry Partner
    Rating - 100%
    132   0   0
    Apr 20, 2008
    10,387
    113
    Avon
    I had a palmetto barrel that would jamb constantly. turned out there was not enough bevel around the chamber. I cut a chamfer on it and it runs 100%. Can you post a pick of the chamber end of the barrel?
     

    duffman0286

    Master
    Rating - 100%
    14   0   0
    Feb 3, 2011
    1,642
    38
    Wayne Co
    I had a palmetto barrel that would jamb constantly. turned out there was not enough bevel around the chamber. I cut a chamfer on it and it runs 100%. Can you post a pick of the chamber end of the barrel?
    i had to do this to my 5.56 saiga to get her to run reliably with hollow points... runs like a champ now and it really didnt take much material of the chamber face to correct the issue
     

    Psode27

    Expert
    Rating - 100%
    4   0   0
    Jan 23, 2011
    1,234
    38
    Rochester
    Good info. Anyone use the 9mm barrel from ADCO? Thats where I was intending to get mine for my build. I didnt realize there was that much difference I guess.
     

    Nicu757

    Marksman
    Site Supporter
    Rating - 100%
    12   0   0
    Sep 2, 2013
    239
    28
    Brownsburg
    yes a QC10 Glock mag 9mm lower and used a Ballistic Advantage 5.5 barrel. I don't think its the mags I used factory and non factory and tried different ones 15 rounders and the 33 rounders. All factory ammo and used 3 different kinds of ball.
     
    Top Bottom