Glock 21 coversion to 10mm

[washagonian]

From your previous post it looked like you were changing out a bunch of stuff.

Yeah, I can see how that might look.

Actually, I was listing all of the slide parts that @oremike suggested might need to be changed out and trying to show which were different and which were the same between an OEM G21 and G20 (there are more parts that BOTH pistols use than people realize - for example, the recoil spring assembly). But I didn't quote his post to give context to my post, so I can see how my explanation was confusing.

Anyway, it's an exercise in just the ZEN of "doing it" (swapping out parts and making the conversion work), more so than it is "practical". The fact that for this particular conversation it is a simple barrel swap (and maybe the extractor), makes it fun to give it a try. More "fun with the gun".

Cheers.

 

[oremike]

Yeah, I can see how that might look.

Actually, I was listing all of the slide parts that @oremike suggested might need to be changed out and trying to show which were different and which were the same between an OEM G21 and G20 (there are more parts that BOTH pistols use than people realize - for example, the recoil spring assembly). But I didn't quote his post to give context to my post, so I can see how my explanation was confusing.

Anyway, it's an exercise in just the ZEN of "doing it" (swapping out parts and making the conversion work), more so than it is "practical". The fact that for this particular conversation it is a simple barrel swap (and maybe the extractor), makes it fun to give it a try. More "fun with the gun".

Cheers.

I just assumed wrongly that to bolt face would be different enough due to the rim size to require changing the slide. Now that I think about it the barrel postions the case on the slide to line up the fireing pin so all you would need is the extractor and maybe the ejector but you might be able to bend that slightly if it doesn't hit the rim.

 

[washagonian]

I just assumed wrongly that to bolt face would be different enough due to the rim size to require changing the slide. Now that I think about it the barrel postions the case on the slide to line up the fireing pin so all you would need is the extractor and maybe the ejector but you might be able to bend that slightly if it doesn't hit the rim.

Regarding the ejectors: the same generations of 20 and 21 use the same trigger housing assembly with the same ejector. Here is the listing from the armorer's parts manual:

Part # 8203: Trigger Mechanism Housing w/ 8196-2 ejector installed - fits G20,G21,G29,G30,G30S,G36

Part # 5406: Trigger Mechanism Housing w/ 8196-2 ejector installed - fits G20SF,G20Gen4,G21SF,G21Gen4,G29SF,G30SF,G30S,G30Gen4,G36FGR,G41Gen4

 

[DirectDrive]

Regarding the ejectors: the same generations of 20 and 21 use the same trigger housing assembly with the same ejector. Here is the listing from the armorer's parts manual:

Part # 8203: Trigger Mechanism Housing w/ 8196-2 ejector installed - fits G20,G21,G29,G30,G30S,G36

Part # 5406: Trigger Mechanism Housing w/ 8196-2 ejector installed - fits G20SF,G20Gen4,G21SF,G21Gen4,G29SF,G30SF,G30S,G30Gen4,G36FGR,G41Gen4

This is where P80 builders can make mistakes.
8203 would be for a pure Gen 3

Glock Trivia :
Although P80 is based on Gen 3 , you have to use a Short Frame (5406) TMH.
"Short Frame" refers to the distance from face of trigger shoe to back of backstrap.
SF frames were brought out during Gen 3 because the original Glock large frames were too big for many shooter's hands.
A Gen 4 with no backstrap installed equals a Gen 3 SF length of pull.

 

[Tlock]

Not a lot of stuff to change out.

I just changed out the barrel.

If I was going to shoot a lot, I spent another 60 seconds changing out the extractor. Given that I shot 10mm through my G21 - maybe - once a month at the range (if that) - the 24 minutes PER YEAR (1 minute to swap in the 10mm barrel and extractor and then 1 minute to swap the 45 ACP barrel and extractor back into the pistol) was well worth the savings of $500 for a G20.

Now - if I was going to shoot a LOT of 10mm, then a dedicated pistol in that caliber makes more sense.

Cheers.

Did g20 mags work for you? He is saying the mags won't work

 

[washagonian]

The G20 and G21 use the same frame. So my G20 mags (feeding 10mm) worked in my G21 frame.

This is exactly the same situation when using a conversion barrel in a 40 S&W G22 (or G23) to convert it to 9mm. The G22 and G17 frames are the same, so G17 mags work flawlessly in a G22 frame when converting to 9mm. Same with the G23 and G19.

Currently I have all three conversions running smoothly:

G22 - 40 to 9
G23 - 40 to 9
G30 - 45 to 10

Cheers.

 

[Tlock]

The G20 and G21 use the same frame. So my G20 mags (feeding 10mm) worked in my G21 frame.

This is exactly the same situation when using a conversion barrel in a 40 S&W G22 (or G23) to convert it to 9mm. The G22 and G17 frames are the same, so G17 mags work flawlessly in a G22 frame when converting to 9mm. Same with the G23 and G19.

Currently I have all three conversions running smoothly:

G22 - 40 to 9
G23 - 40 to 9
G30 - 45 to 10

Cheers.

That's what I've been telling him. He glock is a gen 3 sf, is it possible he got g5 mags and that's the reason they arnt working? I'd drive there and see this with my own eyes but he's in SD and I'm in OR

 

[arakboss]

 

[Twodogs]

That's what I've been telling him. He glock is a gen 3 sf, is it possible he got g5 mags and that's the reason they arnt working? I'd drive there and see this with my own eyes but he's in SD and I'm in OR

My gen-5 mags work fine in my gen-3 gun.

 

[washagonian]

That's what I've been telling him. He glock is a gen 3 sf, is it possible he got g5 mags and that's the reason they arnt working? I'd drive there and see this with my own eyes but he's in SD and I'm in OR

A G20 mag of ANY generation will fit in a Gen 3 short frame G21. Short frame Glocks use the same magazine as standard Glocks. Same goes for Gen 3 standard frame. (See below for explanation of "short frame".)

So, fit and function are not an issue.

It would help to know what he means when he says that the mags are "not working". Ask him specifically what is not working with the mags and post back here.

Does he mean that he's trying to use his G20 (10mm) mags to shoot 45 ACP? If that's the case, of course they won't work - 45ACP won't even load into G20 mag dimensionally designed for a 10mm round.

Does he meant that his G21 mags won't function correctly when trying to shoot 10mm. That would make sense, since G21 mags are dimensionally designed for the larger, 45 ACP round.

In the end - the "conversion" of a Glock 21 from 45 ACP to 10mm, requires - at a minimum - a BARREL swap, and a MAGAZINE swap.

You may already know this, but for what it's worth: "Short Frame" refers to the width from the front of the grip (finger grooves) to the back of the grip (palm swell). The standard size for Gens 1, 2 and 3 were fairly wide. Glock compensated by offering models in "short frame", e.g., "SF" models, for people with small hands, where the distance between finger grooves and palmswell was less.

This changed with Gen 4 and onward. The grip size of Gen 4 models was the same width as a Gen 3 short frame. With the addition of the backstrap capability, a shooter could extend the palmswell back to make the grip larger if wanted.

The dimension of the frame's magazine well was unchanged. Thus, magazines from different generations work in the same model.

In the case of different caliber models using the SAME frame, magazines of different calibers will fit in that pistol's frame. Examples for 9mm, 40 S&W and 357 Sig are: G17 & G22 & G31; G19 & G23 & G32; G26 & G27 & G33.

Examples for 45 ACP and 10mm are: G21 & G20; G30 & G29

There are others as well

Good luck.

 

[DirectDrive]

That's what I've been telling him. He glock is a gen 3 sf, is it possible he got g5 mags and that's the reason they arnt working? I'd drive there and see this with my own eyes but he's in SD and I'm in OR

Glock mags are "backwards compatible"

 

[Tlock]

A G20 mag of ANY generation will fit in a Gen 3 short frame G21. Short frame Glocks use the same magazine as standard Glocks. Same goes for Gen 3 standard frame. (See below for explanation of "short frame".)

So, fit and function are not an issue.

It would help to know what he means when he says that the mags are "not working". Ask him specifically what is not working with the mags and post back here.

Does he mean that he's trying to use his G20 (10mm) mags to shoot 45 ACP? If that's the case, of course they won't work - 45ACP won't even load into G20 mag dimensionally designed for a 10mm round.

Does he meant that his G21 mags won't function correctly when trying to shoot 10mm. That would make sense, since G21 mags are dimensionally designed for the larger, 45 ACP round.

In the end - the "conversion" of a Glock 21 from 45 ACP to 10mm, requires - at a minimum - a BARREL swap, and a MAGAZINE swap.

You may already know this, but for what it's worth: "Short Frame" refers to the width from the front of the grip (finger grooves) to the back of the grip (palm swell). The standard size for Gens 1, 2 and 3 were fairly wide. Glock compensated by offering models in "short frame", e.g., "SF" models, for people with small hands, where the distance between finger grooves and palmswell was less.

This changed with Gen 4 and onward. The grip size of Gen 4 models was the same width as a Gen 3 short frame. With the addition of the backstrap capability, a shooter could extend the palmswell back to make the grip larger if wanted.

The dimension of the frame's magazine well was unchanged. Thus, magazines from different generations work in the same model.

In the case of different caliber models using the SAME frame, magazines of different calibers will fit in that pistol's frame. Examples for 9mm, 40 S&W and 357 Sig are: G17 & G22 & G31; G19 & G23 & G32; G26 & G27 & G33.

Examples for 45 ACP and 10mm are: G21 & G20; G30 & G29

There are others as well

Good luck.

He says the g20 mags won't stay in the gun and just fall out. He hasn't even got to the shooting part.....I tried to get him to buy a 20 or 40 and just have a functional firearm instead of screwing with converting it. I'm not a glock expert by any means and I've been telling him all this.....appreciate the response

 

[DirectDrive]

He says the g20 mags won't stay in the gun and just fall out. He hasn't even got to the shooting part.....I tried to get him to buy a 20 or 40 and just have a functional firearm instead of screwing with converting it. I'm not a glock expert by any means and I've been telling him all this.....appreciate the response

First, I'd verify that an empty mag will lock in.
If yes,then try short-loading the mag by one round.
Give the mag a little smack if needed.

 

[Tlock]

That's the same thing I told him.....he said he was trying with a empty mag..thanks guys. My last message to him was to take it to a shop

 

[oremike]

He might have switched the mag release to the other side and early Gen magazines only have the one cut out while gen 4&5 have 2 cutouts.

 

[UNO]

Just to resurrect this thread. I have a g21and I run a lone wolf 10mm conversion barrel in it with a 10mm magazine. Works great. Also have a 24lbs recoil spring too because the slide is a little lighter than the 20. Some of the suuuuper hot underwood loads will have a hiccup (not eject properly) about 1% of the time. But not bad for just a barrel and mag change. Gun shoots 10mm, 40s&w, 45acp and 45 super with just one extra barrel. Super versatile build. If you're a reloader you can do 460 rowland, 40 super, 9x25 dillon as well.