Gen 4 G20 and G21 barrels interchangeable?

[Jstudz220]

I was browsing the Internet last night out of curiosity to see what conversion barrels were available for the Glock 21. I stumbled across Glock forum and several of the members were saying all you have to do is simply buy a gen 4 Glock 20 barrel and that’s it. I knew the guns were the same dimensions but never thought that this would actually work. Apparently it doesn’t work with the gen 4 models only. Does anyone have any experience or insight on this they can share?

 

[pdugas]

https://www.thetruthaboutguns.com/frankenglock-10mm-45-glock-21/
https://www.glocktalk.com/threads/glock-21-conversion-to-10mm.1703321/ .

From what I can gather, Converting a G21 to a 10mm is just a matter of changing the barrel , recoil spring and maybe the mag . Going the other way, 10mm to .45 requires a complete slide swap because of the larger barrel size of the .45. Some of the info out there is older info and was put out before the Gen 4. came out. I have a Gen 4 G20 I wanted to convert to .45 but didn't want to spend the extra $$$ on complete slide, barrel and mag. However I can run .40 cal through my 10 mm and it functions flawless. Hope this helps and good luck.

 

[Jstudz220]

https://www.thetruthaboutguns.com/frankenglock-10mm-45-glock-21/
https://www.glocktalk.com/threads/glock-21-conversion-to-10mm.1703321/ .

From what I can gather, Converting a G21 to a 10mm is just a matter of changing the barrel , recoil spring and maybe the mag . Going the other way, 10mm to .45 requires a complete slide swap because of the larger barrel size of the .45. Some of the info out there is older info and was put out before the Gen 4. came out. I have a Gen 4 G20 I wanted to convert to .45 but didn't want to spend the extra $$$ on complete slide, barrel and mag. However I can run .40 cal through my 10 mm and it functions flawless. Hope this helps and good luck.

Thanks for the info, I appreciate it.

 

[Shoemaker1955]

I have a 10mm Threaded and Fluted Rock Slide
Fits 20-21 Glocks
Black Barrel
Sell for $160.00

 

[Shoemaker1955]

Oops
I meant a Barrel
I do have rock Slide for 20-21 but this is the 10mm Barrel
The Slide is FDE
RMR cut
Slanted ports
Night dihhts
New

 

[Jstudz220]

Oops
I meant a Barrel
I do have rock Slide for 20-21 but this is the 10mm Barrel
The Slide is FDE
RMR cut
Slanted ports
Night dihhts
New

Do you know if it will fit in a gen 4 G21 slide? I’ve read that most aftermarket barrels for the G20 will not fit into the G21 because the hoods are slightly different.