WTK- Anyone convert a Glock 21 .45 to Glock 20 10MM?

[Redbos99]

Hi All,

I have a 3rd Generation G21 and have been doing some research on buying a G20 "Upper" to convert to 10MM. I have been seeing some conflicting info out there and wanted to know if anyone has tried this? I know I would need to get G20 mags, but with the new top end, would be I be good to go? I also understand that the G21 platform uses the same ejector as the G20 platform. Also, anyone know where I can find a good supply of Pre ban G20 mags? Dont see many around that often..........

Thanks very much for all the help!

Will
email: [email protected]

 

[EddieCoyle]

You don't need an upper. Just get a barrel from KKM Precision.

 

[ShadeWPI]

I believe the Model 20 and Model 21 use the same frame.

The Model 21 slight is lighter so it works with the lower recoil of the .45 ACP round.

As for pre-ban Model 20 magazines, that might be a little tricker. The Model 20 was introduced in mid 1991 so you're limited to only 3 years production.
The seond trick is identifying a pre-ban and a post-ban magazine as I don't believe there are any tell-tale signs outside of the "during-ban" Markings - "For LEO and Government Use Only" markings above the caliber markings on the magazine.

 

[ShadeWPI]

EC,

Have you tried the barrel swap? I haven't so I wasn't sure how well the lightly slide worked with the higher power 10mm loadings. You should be able to compensate with a higher weight recoil spring if there is a problem though.

 

[Redbos99]

Yes, I have heard both online during my research. I read some articles that said that you need a 10MM slide because of the weight difference. But then I read a bunch of articles saying just what Eddie stated. I would like as much info as you have!

Thanks - Will

 

[Mike-Mike]

I have heard about this barrel change. Wouldn't the extractor be off by about .025" ?

 

[lupis42]

You don't need an upper. Just get a barrel from KKM Precision.

Does that go the other way as well?

 

[Redbos99]

From what I have read, I do not think the G20 can be converted. Really interested to know if should buy I new Slide and all? Thanks for the info, please keep it coming.

Will

 

[EddieCoyle]

I didn't convert a G20, but I did convert a G30 to 10mm. I had to remove a bit of material from the extractor to get it to grab the rim of the 10mm, but that was easy and it works flawlessly. It still works as a .45 when I put the G30 barrel back in. I didn't have to change the slide or the recoil spring. I do have to use G29 magazines with the 10mm barrel.

The G20 and G21 use the same recoil spring, and I doubt that the slide weight is different enough to worry about.

 

[lsbbigdog]

The breech face ,extractor,and ejector is different . I have read that KKM 10mm barrel, 21# Wolf recoil spring, and a couple of G20 magazines have worked pretty good.