9mm in .40 mags?

Discussion in 'Glock Forum' started by miamivice, Aug 28, 2012.

  1. miamivice

    miamivice New Member

    14
    0
    I'm wondering how well the 9mm rounds fit and feed in the 40 mags. Here in canada we are limited to 10 rounds max in any cal. However, stuffing 12-14 9mm rounds in a 40 mag would be perfectly legal:rolleyes:
     
  2. jimmyalbrecht

    jimmyalbrecht Glockn Rollin

    Lol I mean they would feed but not perfectly reliable. If you're talking about at the range then it would work good enough. Of course you're not really allowed to protect yourself up there so it wouldn't really matter if it fed 100% lol.
     

  3. Tape

    Tape New Member

    654
    2
    they will not work, they are too narrow and will slip through the 40 magazine and double feed, I already tried
     
  4. miamivice

    miamivice New Member

    14
    0
    No Kidding.....Welcome to the "People's Republic Of Ontario"

    Thanks, it was worth a shot.
     
  5. jimmyalbrecht

    jimmyalbrecht Glockn Rollin

    There are plenty of people who do this when they convert their .40 cal Glocks to 9mm with a conversion barrel. Like I said it isn't 100% reliable lol, but it will get the job done in a pinch and not in a situation where your life depends on it, I'd say it has the same failure rate as an aftermarket cheap 9mm magazine haha.
     
  6. Tape

    Tape New Member

    654
    2
    they use a 40 magazine and barrel or a 9mm mag and barrel, he is asking if a 9mm will fit in a 40 mag and the answer is no
     
  7. Tape

    Tape New Member

    654
    2
    put it this way, if you are in a situation where your life is at stake and all you have is a g22 and empty magazine with 100's of 9mm ammo laying around, yes I would do whatever is possible, if you have a choice for your edc NO I would not do it.
     
  8. jimmyalbrecht

    jimmyalbrecht Glockn Rollin

    They use .40 mags with 9mm barrel, but as I stated, he lives in Canada. EDC is not an issue or an option because they can't carry weapons.
     
  9. miamivice

    miamivice New Member

    14
    0
    Yepper, i have a Glock 17 Gen 4 and i have a .40 mag laying around, so i was wondering if the 9mm will fit and feed well enough to use it.
     
  10. BORIS

    BORIS New Member

    789
    0
    Then give it a try and let us know how it works ;)

    Back in the dark ages of the decade long ban here I knew a few fellows that used Beretta 96 mags in their 92s and they never had a single problem.

    Let us know how it works out...
     
  11. Wes1969

    Wes1969 New Member

    2
    0
    I've seen it done. 9mm loaded in a G22 mag. I was told by a firearms instructor about a guy who fired off a few 9mm rounds through an HK USP 40.
     
  12. I use my g23 mags in my G19 all the time at the range, and it's never had a FTF or any other issue. I would not necessarily use it to carry, but at the range, it works well. Never actually tried to see how many rounds I could stuff into it. I typically only load 10 rounds per mag at the range.
     
  13. Tape

    Tape New Member

    654
    2
    loading 9mm rounds into a .40S&W, I could not even get 1 more round in the .40S&W magazine, the difference between the two cases is 0.032

    the 9mm diameter 0.392
    the .40S&W diameter 0.424
     
  14. Ghost23

    Ghost23 New Member

    I'm trying to see how this could be.
    A 9mm bullet is .355" in diameter. A .40 is .401" in diameter.
    .392 - .355 is .037, and .424 - .401 is .023.
    That would mean the casing on the 9mm is .037", and the casing on the .40 is .023".

    Now if a .40 has a higher pressure, wouldn't it need a thicker casing?

    I absolutely could be wrong, so if I am, someone correct me. I'm really interested in this.
     
    Last edited: Aug 29, 2012
  15. BORIS

    BORIS New Member

    789
    0
    40 and 9mm operate at the same psi. Unless you shoot +P 9mm, then the 9mm will be higher in psi.
     
  16. miamivice

    miamivice New Member

    14
    0
    Nevermind, changed my order to the Glock 22 Gen 4. At least now i don't have to buy an extra mag :D