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Can a Glock 20 be converted to 45 ACP?

Discussion in 'Handguns: Autoloaders' started by Lone_Gunman, Mar 24, 2006.

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  1. Lone_Gunman

    Lone_Gunman Member

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    Can the barrel and mag on a G20 be swapped out with the barrel and mag of a G21 to allow it to shoot 45 ACP?
     
  2. Phantom Warrior

    Phantom Warrior Member

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    It's been a while since I've looked into this. I had the same question w/ 9mm on a .40 frame.

    I'm going to say no because, as someone pointed out to me, the breech face dimensions are different. A .45 ACP round won't fit onto the face of a 10mm slide and the extractor probably won't fit either.

    I believe you can put a full .45 ACP upper (slide & barrel) onto the 10mm lower, but the cost of doing that would be close to the cost of simply buying a complete Glock 21.
     
  3. RyanM

    RyanM Member

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    I dunno about the breech face dimensions, since it's possible to get 10mm conversion barrels for the G21. But I'm pretty sure the hole in the end of a G20 slide is too small for a .45 barrel.

    For converting .40 to 9mm, at least, all you need is an aftermarket conversion barrel (the hole in the slide is too big for an OEM 9mm barrel), and a new trigger parts housing (with ejector).
     
  4. Lone_Gunman

    Lone_Gunman Member

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    Are you sure about that? I twould have figured the hole in the slide was the same, and that the difference was made up by the fact that the walls of the 10 mm barrel were thicker... but I dont know for sure.

    Thats the way it works with 10 mm 1911s any way.
     
  5. Walt Sherrill

    Walt Sherrill Member

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    Converting .40 to 10mm.

    You may need more than the barrel.

    In a small-framed gun, like a Glock 22, you need a larger frame that will accomodate the larger mags, needed for the longer round.

    On a gun that was designed for .45, you can move down (if you find suitable mags). ON a gun designed for 9mm or .40, the best you'll do is .40 -- and then only if the slide will accomodate the barrel. (EAA guns have interchangeable 9mm/.40 barrels, and they function fine that way. With many other guns, the barrel opening in the slide isn't right to accept the larger diameter barrel.)

    For most caliber conversions, there is the question as to whether headspace will be right and whether the extractor will work. (Not generally a problem with .40/10mm conversions.)

    Its not a slam dunk, and for some guns, A LOT MORE THAN JUST GETTING THE BARREL!

    Most .45 barrels are much larger (in diameter) than most .40 or 10mm barrels. Don't assume they will swap. Many gun makers require the entire top end to be replaced, when the frame will handle the load.
     
  6. RyanM

    RyanM Member

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    That's because the 1911 was originally designed for .45. 10mm 1911 barrels have to be made extra thick to fit in the original bushing. Barrels in guns originally made for 10mm (like the G20) will be as thick as necessary to keep from blowing up. And they don't need to be the width of a .45 barrel for that.

    Considering that the G20 was made before the G21, and that the 9mm and .40 cal Glocks have different slide hole sizes, it's a fair bet that the G20 and G21 slides also have different sized holes.
     
  7. Lennyjoe

    Lennyjoe Member

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    I don't believe so. You can convert a G21 to shoot 10MM but not a G20 to a .45 as far as I can see.

    Here's a thread at glocktalk pertaining to going from .45 to 10MM

    A quote from the thread; "Nope, the breach face on a 10mm slide is .433" wide and a .45 slide is .483" wide. The barrel hood is cut to fit the slide breach face so the 10mm hood is .425" wide and the .45 is .475" wide."


    http://www.glocktalk.com/showthread.php?threadid=317427
     
  8. Soybomb

    Soybomb Member

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    To my understanding you can make your 45 glock fire 10mm or your 10mm glock fire .40 pretty easy. Past that you need a new slide at the least.

    To me 10mm firing .40 for cheap practice/fun seems ideal.
     
  9. doublebarrel

    doublebarrel Member

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    AFAIK, G20/G21 pair have the same identical frame, just like the G29/G30 twin. Even the dog leg ejector is the same(same part number), and they use same weight recoil springs. So swapping the slide and get new barrel is all it takes to shoot the other caliber...
     
  10. PO2Hammer

    PO2Hammer Member

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    10mm to .45acp requires a complete upper assembly (slide, barrel etc...)
    .45acp to 10mm requires a KKM CONVERSION barrel. A heavier recoil spring (because the 21's slide is lighter) and a 10mm extractor are recomended.
    10mm to .40s&w or 357sig requires only a conversion barrel and works very well.
     
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