Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
11/28/2012 10:50:13 PM EDT
I had a Glock 21 several years ago that i've since sold but I remember people talking about how you can swap barrels and mags in certain Glocks to change calibers.  I recently purchased a replacement G21 that's a Gen 3 and I was wondering what calibers, if any, would work in it after swapping barrel and magazine? Thanks :-)
11/28/2012 10:59:41 PM EDT
[#1]
With the same mags, .45 Super, .400 Corbon, .40 Super, and .38/45 Clarke.

I'm not sure if the external barrel dimensions are the same on the G20 and G21, so you might need a complete 10mm upper along with mags to shoot 10mm.  Or if anyone offers it a 10mm conversion barrel.  With the Glock 20 upper you could then shoot 9x25 Dillon, .357 Sig, .40 S&W, and .224 Boz with the appropriate barrels.
11/28/2012 11:03:33 PM EDT
[#2]
Evidently a lot of people buy the 40 cal glocks, buy 9mm conversion barrels, and are able to have one gun that uses both calibers.  I have some qualms about this myself....but admittedly haven't tried it.
11/29/2012 3:55:02 AM EDT
[#3]
A G20 barrel will fit in a G21 slide; however, the barrel hood will have a little space on both sides.  There are 10mm conversion barrels for G21s and G30s   Some say they had to modify their G21/G30 extractors, in order to shoot the 10mm; others say it's a 109% perfect drop-in, with no modifications necessary.  

This thread has nothing to do with .40/9mm conversions.
11/29/2012 4:19:56 AM EDT
[#4]
Quoted:
Evidently a lot of people buy the 40 cal glocks, buy 9mm conversion barrels, and are able to have one gun that uses both calibers.  I have some qualms about this myself....but admittedly haven't tried it.


I've done it with a G22 and lone wolf 9mm barrel and have had zero issues. it works so well that i just bought one for my G23.
11/29/2012 9:41:16 AM EDT
[#5]
So if you swapped the slide, barrel and mag you should have pretty seamless transition to 10mm?  The  extractors seem to work with the 10mm from what I've read today so I guess that's the wild card.  I'm not planning on doing a conversion but it's always nice to know all the possibilities just in case.

Thanks for the info guys :-)