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Today’s video is quite different from my normal testing. In this installment, I attempt to create the world’s first 9mm conversion of a .45 ACP GLOCK 21… a FrankenGLOCK. As far as I know, having Googled and consulting two GLOCK armorers, this hasn’t been done be-fo. One even told me it can’t be done. My purposes for wanting to try are similar to many folks who attempt wacky projects . . .

1) For the hell of it
2) Because I am cheap

What I really wanted was a long-barrel 9mm pistol for ammo testing purposes, GLOCK isn’t currently making a G17L, and I didn’t want to spend $600 for a test pistol. Thanks to Lone Wolf’s conversion barrel, I had hope for a much lower cost alternative. While the result isn’t perfect, it surpassed my expectations and it will certainly serve the purpose.

Now I’m inspired to convert this G21 into a do-everything pistol. Future installments will show my attempts to convert it to 10mm, to .40 S&W, to 460 Rowland, and even to a .50-caliber 50GI.

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  1. Why doesn’t he just use a 6″ barrel in a G17? Sure, he can make all the major calibers shoot off one frame, with some of them not working correctly. Or he can just bring 2 or 3 frames to the range, have everything work all hunkydory and not make a 5 minute video about how he really didn’t do anything to make this happen past putting a barrel in a gun.

    • “Why doesn’t he just use a 6″ barrel in a G17?”

      Because I don’t have a G17. And I already had the G21.

      The G17 (actually the G17L) was the obvious answer to the question, and I did consider getting it. However, the 17L isn’t currently manufactured, and getting a 17 plus a 6″ barrel was about a $700 proposition. Going with the conversion for the G21 was about $150 total, all in.

      Now, the G17 would have been an ultimately reliable, ultimately “proper” way to go, yes. But … that’s all it would ever be, is a 9mm. You can’t convert the 17 to anything else. So I’d have a very expensive solution to my 9mm dilemma, and nothing else. I actually thought about going with a G22 and a conversion barrel, as that would have at least added .40 S&W to the mix, but I’d still be out $700.

      Whereas with the FrankenGlock approach, with that same $700 budget, I’ve still got $550 left. That should be about enough to get me a conversion to 10mm, and to long-barrel .40 S&W, and to .460 Rowland. One gun, five calibers, five testing platforms (plus the options to go to .22lr and .50 GI in the future).

      The world’s most practical solution? Probably not. But, as put in the title of the vid, it’s an experiment…

  2. Just because I refer to mine with adoring affection as “a railroad tie with grip” or the fact that it’s also dishwasher safe, and qualifies as suitable for proper pistol whipping ability, and, and, etc,…
    Oh good grief,…

    • Yep, that’s what I’ve got my eye on. I’d like to get that conversion, and then compare how the stock G21 compares against the 50GI version, to see how much you gain from the mammoth cartridge.

  3. Good video for purely scientific purposes. Especially liked the WD reference. Now try some self defence ammo out it in gel and chart the results with the higher velocities.

    • That’s the plan, is to conduct future testing of self-defense ammo from the 3″, 4″, and 6″-barrel platforms. That way we can know how the ammo is more likely to perform out of any gun the viewer may have.

  4. My company car is a FrankenFord. Why not a frankenglock. And if you had screwed it up? Who cares? It’s 600 bucks of compressed cheez whiz. Not something of real value. (I give full credit to DG for the cheez whiz discription, very apt, of the glocks.)

  5. That does say something about the Glock. Ugly, blocky and as fun to carry as an I-beam, but like Billy Dee says, works every time.

  6. “What possible validation is there for this?” “There is no good reason”

    As far as I’m concerned, that’s the best reason of all!

    Thanks for the great videos, all of them.

  7. I liked it. I have shot .40, 9mm, .357 sig, and .22 out of my 23. If I had the bigger frame, (20,21) I would add .45 and 10mm, as well as the .460 Rowland and 50gi to the list. Imagine 8 calibers out of 1 gun! Epic versatility!

    • Exactly. It may be a little insane, but this notion appeals to me, not from a purely practical aspect, but just for the fun of it. The gun already shoots .45 ACP, and now 9mm, and — one shot at a time, it can handle .380 ACP (won’t cycle or feed, but it’ll at least fire the one you rack into the chamber… I mean, I had to try it, right?) Conversion barrels for 10mm, .40, and .357 Sig are readily available. And there’s a conversion kit for .22lr, .460 Rowland, and 50GI. So that brings the possible caliber choice up to 9…

      Unlike the sketchy nature of the 9mm conversion, the 10mm, .40, and .357 Sig, .460 Rowland, 50GI, and .22LR should be perfectly reliable and perfectly valid.

      And if you want to go with less-familiar cartridges, there’s also conversion barrels to 9x25mm (9×25 Dillon), .38 Super, 40 Super, and .400 Corbon…

      I think it’s fun, but I also recognize that you would have to be really careful in such a situation, you’d never want to load .357 sig in the mag while the .40 barrel was in the gun, etc…


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