Glock 21 10mm conversion barrel

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  • Jstudz220

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    I got a notification a couple weeks ago from glockstore that the double diamond conversion barrel they sell was back in stock. According to the directions and user feedback, all that’s required to convert a G21 chambered in .45acp to shoot 10mm auto is a simple barrel swap. All you need is the barrel and a Glock 10mm magazine. A handful of different reviews I’ve read say it just as a Glock should. A couple mention getting a slightly heavier RSA or maybe changing out the 45acp extractor with a 10mm extractor but according to the manufacturer and most reviews that’s not necessary. Does anyone have any experience with this barrel specifically or experience with converting a Gen 4 G21 to shoot 10mm?


     

    Jstudz220

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    Well anyway if anyone is curious and wants to follow along I plan on making into a hog hunting gun. The barrel should hopefully be here by the weekend. Today I picked up 200 rounds of Sig 180gr fmj. After doing a decent amount of research it seems to be one of the few big box brands loaded closer to 10mm potential. I’m not sure if I’m going to settle on Underwood or Buffalo Bore to carry but my plan is to see how it runs with the hot range ammo first. Assuming all goes well I’ll order 100 rounds or so of my desired carry ammo and take it to the range again to run 3-4 magazines through the gun.

    As the gun sits now it’s a gen 4 Glock 21 completely stock with the exception of the sights I put on a pair of Ameriglo operators. I’ll be sporting a surefire x300 on it and have been toying with the idea of sending it off to be cut for a rmr. If I don’t send it off to be cut for a rmr I’m going to go with a Leopould delta point micro.
     
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    Jstudz220

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    10mm barrel came in today. Looks really nice.
    IMG_5361.jpeg
    IMG_5362.jpeg
    IMG_5355.jpeg
     

    Jstudz220

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    Wonder if this would work with a Gen 1 Glock 21?
    According to the link I attached earlier in the information about it is says yes.

    One Glock, Two Calibers!
    Easily convert your .45 Caliber Glock to shoot 10mm in seconds!

    Designed to allow shooters to change calibers by simply dropping in the Double Diamond conversion barrels in conjunction with the appropriate caliber magazine. The barrel is cut to fit in the ejection port of the intended slide. Basically, it's a .45 caliber barrel on the outside chambered in 10mm ... brilliant!

    Swapping out recoil guide rods, ejectors, extractors, or strikers is not necessary.

    Please note: In-stock availability of our GSPC barrels may be limited. If your order is time sensitive, we recommend contacting us to verify quantities.

    Fits Gen1-4 models.

    The "30/30SF" option will NOT fit the G30S.
     

    Jstudz220

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    I'm glad it worked out, but what do hope to gain switching to 10mm. You can buy or load your own, .45acp super loads and shoot in a glock with no modifications.
    I don’t reload and as stated I plan to hunt hogs with it. 45 super isn’t nearly as easy to obtain as 10mm. I spent months searching the internet for 45 super in stock before I gave up on that. So the main reason in choosing 10mm over 45 super comes down to 10mm being main stream and 45 super being a niche hard to obtain round.
     

    Jstudz220

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    I finally got a chance today to try out the 10mm conversion barrel. I shot 150 rounds of sig 180gr fmj. I experienced 1 malfunction where the last round failed to feed. I was able to replicate the malfunction once again loading 2 rounds at a time. The ejection pattern was a little odd with the 10mm, it threw the spent brass directly back at me either right over my head or over me left shoulder. Other than that the gun shot fine.
     

    Batwing6

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    As soon as you find out what caused that to happen, please post! I'm following this story as I want to do the same thing!! Good Luck with it.
     

    Jstudz220

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    Out of 150 pieces of brass only 11 are disfigured like this. It looks like it was getting mangled when I was replicating the last round not feeding. All of the primers look fine and the other 139 pieces of brass look fine as well. That’s my only guess as to what caused it.
     

    Batwing6

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    How accurate was it? I plan to do the same thing with my Glock Gen4. I have a Glock G23 with a 9mm conversion barrel and it works fine.
    If I may chime in on this, I have a G27 Gen4 and I have a 9mm and a 357 SIG barrel from Storm Lake and have not once had a problem. I also have a G22 Gen4 with a stock 357 SIG barrel stuffed up in it and again no problems Thanks
     

    Martman300

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    Late to the party, and may be a dying post. I actually landed here with a Google search.

    I just saw a video about converting the G21 to 10mm, then late in the video/comments mentioned the same setup to shoot 40.

    Now it has me thinking is that possible? If the G21, can shoot 10mm & 40, the 357 Sig should be no problem. Provided an appropriate conversion barrel is available.

    I know that’s available for the G23 & G27. 9mm, 40, or 357 Sig.
     
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