Convert Glock 20 to 21?

[spistols]

Is it that easy to just drop in a G21 .45 barrel and use G21 mags into a G20, to shoot .45 out of a G20 frame/slide?

Does Gen 3/4/5 matter or the Gens have to match up?

 

[alex4922]

Dunno bout that but you can save a bit of cash by buying up all the.40sw guys are dumping. Great for range fodder and all my G 10mm's eat it up.

 

[medium187mph]

Is it that easy to just drop in a G21 .45 barrel and use G21 mags into a G20, to shoot .45 out of a G20 frame/slide?

Does Gen 3/4/5 matter or the Gens have to match up?

Short answer- No

Great explaining below from another source

“ Just changing the barrel and the mag won't do it. The breach face and the muzzle barrel hole on the G20's slide is too small to accommodate a .45ACP case head and a .45ACP diameter barrel. Same reason why you can't shoot .40S&W out of a slide made for 9mm. Now if you were to find a complete G21 upper (full G21 slide and barrel assembly), then you could use it with your G20 frame/receiver (along with a G21 mag(s)). The problem with finding complete Glock uppers, is they're hard to find (got to be on the look out for one on GlockTalk's gun accessories classifieds forum section) and when you do find someone selling one, you can usually buy a complete used Glock (in this case, a good used G21) for just a little bit more money (thus not making it worth it most of the time (however, uppers don't require shipping to an FFL, so you do save some FFL transfer fee money there)).“

 

[6Bones]

Short answer- No

Great explaining below from another source

“ Just changing the barrel and the mag won't do it. The breach face and the muzzle barrel hole on the G20's slide is too small to accommodate a .45ACP case head and a .45ACP diameter barrel. Same reason why you can't shoot .40S&W out of a slide made for 9mm. Now if you were to find a complete G21 upper (full G21 slide and barrel assembly), then you could use it with your G20 frame/receiver (along with a G21 mag(s)). The problem with finding complete Glock uppers, is they're hard to find (got to be on the look out for one on GlockTalk's gun accessories classifieds forum section) and when you do find someone selling one, you can usually buy a complete used Glock (in this case, a good used G21) for just a little bit more money (thus not making it worth it most of the time (however, uppers don't require shipping to an FFL, so you do save some FFL transfer fee money there)).“

I’ve had great luck on GunBroker scoring occasional deals on complete slides. Believe it or not, I’ve even scored some on eBay. Hoping to find one ODT is a lost cause these days. So many tire kickers and ghost buyers!