Nobody makes a conversion barrel (40sw) for a g-21? But they do for a g20 :o :o
There is another thread that is dealing with the same root issue.
Extractor groove diameter of the 9mm, 40S&W and 10mm is all the same: .340". The 45 ACP is .400". This makes downsizing a 40 to 9mm easy, but 45 to 10 or 40 a challenge because the extractor may not reliably grab the rim.
You should look for a glock 20 barrel short chambered in .400" This could be finish reamed to either 40 S&W or 10mm. Might have to call around to the various makers, but I bet Storm Lake or Lone Wolf could make one for you very easily. That is how they have to start.
I was reading somewhere that the gen 3 g21's had a updated extractor that works well with 10mm conv. that i already have in my g21. I was hoping to conv. the g21 to 40sw also.
Aren't the barrels interchangeble?G20 should fit the g21,so any barrel that fits g20 should fit the g21,correct?
Quote from: dougx on June 30 2012 07:50:24 AM MDT
Aren't the barrels interchangeble?G20 should fit the g21,so any barrel that fits g20 should fit the g21,correct?
The barrels will "fit", but the 10mm case head doesn't fit the G21 breach, and the extractor won't engage. It'll need a G20 slide (which also fits), or modification (extractor).
Gee! Haven't had any problems with my g-21 slide. :o
Quote from: Grizzz on June 30 2012 11:17:56 AM MDT
Gee! Haven't had any problems with my g-21 slide. :o
Me neither, but I wouldn't rely on it. "It works" is a long way from practical.
I think the 10mm conversion barrels made for the G-21's have a larger diameter at the muzzle to accomedate the opening in the slide where the barrel sticks out. ??? No barrel bushing in the Glock... :-[
Someone correct me if this is incorrect! :-X
Quote from: The_Shadow on June 30 2012 11:25:31 AM MDT
I think the 10mm conversion barrels made for the G-21's have a larger diameter at the muzzle to accomedate the opening in the slide where the barrel sticks out. ??? No barrel bushing in the Glock... :-[
Someone correct me if this is incorrect! :-X
The 10mm barrel will fit with a barrel bushing. I haven't heard of anyone using them in years, since the increased availability and lower cost of aftermarket barrels that just fit and shoot. I was referring to a 10mm conversion barrel I had and sold, addressing the extractor issue. For maximum versatility, one frame, both slides, and a healthy collection of barrels and springs is the best way to go. It'll give the option of shooting everything from 9mm to 45 Supers, and everything in between.
So, if i bought a 10mm long slide, would it fit my G-21 frame?
Yes. The uppers and lowers are interchangeable between g20 and g21.
Quote from: Grizzz on June 30 2012 12:10:40 PM MDT
So, if i bought a 10mm long slide, would it fit my G-21 frame?
Do you think you are going to give it a go? As sqlbullet said it shouldn't be an issue whatsoever. I'll be interested to know if it turns out for you if you do. Certainly keep us posted if you move forward with it.
Quote from: DM1906 on June 30 2012 11:48:11 AM MDT
Quote from: The_Shadow on June 30 2012 11:25:31 AM MDT
I think the 10mm conversion barrels made for the G-21's have a larger diameter at the muzzle to accomedate the opening in the slide where the barrel sticks out. ??? No barrel bushing in the Glock... :-[
Someone correct me if this is incorrect! :-X
The 10mm barrel will fit with a barrel bushing.
No, not correct. The G20 and G21 barrel diameters are the same. No barrel bushing needed.
The only external dimension that's different between a 20 and 21 barrel is the barrel hood, which is narrower on the 20 barrel. A 20 barrel fits a 21 slide fine; the rear of the barrel is located by the sides of the slide, not the barrel hood, but that doesn't seem to matter.
The gen 3 G21 extractors do engage the 10mm and 40 S&W case heads as well. Sliding a 10mm case under the extractor on a 21 slide seems like it's too loose, but when the case is located by the barrel, it works fine. Mine functions 100% with 10mm and 40 S&W with a G20 barrel in the G21 slide. The only difference I've noticed is sometimes brass is ejected back over my head instead of out to the side.
To answer the OP, you can use a G20 40 S&W conversion barrel in the G21 slide with no other modifications, and it will work. You'll have to use g20 mags of course. You could also just use a 10mm barrel and shoot 40 S&W in it, no need for the conversion barrel;
this is ok in a Glock only.
Quote from: Grizzz on June 30 2012 12:10:40 PM MDT
So, if i bought a 10mm long slide, would it fit my G-21 frame?
Yes. That's what mine is.
Quote from: Yondering on July 05 2012 05:11:57 PM MDTNo, not correct. The G20 and G21 barrel diameters are the same. No barrel bushing needed.
You're right. Brainfart. Like I said, many years ago. May have been first gen vs. 2, or another caliber. Tried the Gen2 21 and Gen3 20 a few days ago, and they fit. A couple FTF's with the 10mm barrel in the 21 with 21 slide, but shot well otherwise.
This discussion has me thinking of some things to look at between the G-29 and G-30...I do some looking tomorrow! ???
I've got to try the 40sw in my g21 x 10mm conv. barrel !! ;D ;D
Yondering, had pointed out a few things that got me thinking (I know that can be Dangerous ;D), now that I have both the 29 & 30... ???
Today, I took apart the G-29 and the G-30 to compare things...
The slides will fit on either frame
Magazines will fit either frame
The barrels DO NOT interchange, however the 10mm barrel will fit into the G-30 slide...As mentioned the barrel hood of the G-30 45ACP barrel is wider and so is the notch to match where it rides in the G-30 slide. That is why the 45 barrel does not fit the G-29 slide, the notch in the G-29 slide is not wide enough to allow it to drop in.
Barrel diameters were the same... so the opening in the front of the slide are equal.
Quote from: The_Shadow on July 06 2012 02:01:17 PM MDT
The barrels DO NOT interchange, however the 10mm barrel will fit into the G-30 slide...As mentioned the barrel hood of the G-30 45ACP barrel is wider and so is the notch to match where it rides in the G-30 slide. That is why the 45 barrel does not fit the G-29 slide, the notch in the G-29 slide is not wide enough to allow it to drop in.
Barrel diameters were the same... so the opening in the front of the slide are equal.
Correct, the 10mm barrel fits the 45 slide, but not the other way around. The 45 case head wouldn't work in the 10mm slide anyway.
Quote from: DM1906 on July 05 2012 10:58:00 PM MDT
Quote from: Yondering on July 05 2012 05:11:57 PM MDTNo, not correct. The G20 and G21 barrel diameters are the same. No barrel bushing needed.
You're right. Brainfart. Like I said, many years ago. May have been first gen vs. 2, or another caliber. Tried the Gen2 21 and Gen3 20 a few days ago, and they fit. A couple FTF's with the 10mm barrel in the 21 with 21 slide, but shot well otherwise.
You're thinking of the 9mm and 40 Glocks. The 40's have larger barrel diameters, so converting to 9mm requires a conversion barrel.
And this is why I advice fence sitters to get a G21. I love the 10mm, but if someone isn't all in, they are better off with a G21 that they can get a barrel for, and a slide if they really want the full conversion.
Quote from: Yondering on July 06 2012 02:21:13 PM MDT
Quote from: DM1906 on July 05 2012 10:58:00 PM MDT
Quote from: Yondering on July 05 2012 05:11:57 PM MDTNo, not correct. The G20 and G21 barrel diameters are the same. No barrel bushing needed.
You're right. Brainfart. Like I said, many years ago. May have been first gen vs. 2, or another caliber. Tried the Gen2 21 and Gen3 20 a few days ago, and they fit. A couple FTF's with the 10mm barrel in the 21 with 21 slide, but shot well otherwise.
You're thinking of the 9mm and 40 Glocks. The 40's have larger barrel diameters, so converting to 9mm requires a conversion barrel.
No. Wouldn't have done that. I think it may have been the .40 and .45. That's all that was available/allowed at the dept. in about 92. The more I think about it, the more I remember what didn't work. There were no conversion barrels then, that we knew of, so it was all mix (mis)-matching available original parts. There was one working "conversion" at the time, and I think it was the .40 in a .45. All moot at this point, with the availability of simple conversions. I wasn't a Glock fan, at all, until about that time.
Quote from: DM1906 on July 06 2012 02:53:02 PM MDT
Quote from: Yondering on July 06 2012 02:21:13 PM MDT
Quote from: DM1906 on July 05 2012 10:58:00 PM MDT
Quote from: Yondering on July 05 2012 05:11:57 PM MDTNo, not correct. The G20 and G21 barrel diameters are the same. No barrel bushing needed.
You're right. Brainfart. Like I said, many years ago. May have been first gen vs. 2, or another caliber. Tried the Gen2 21 and Gen3 20 a few days ago, and they fit. A couple FTF's with the 10mm barrel in the 21 with 21 slide, but shot well otherwise.
You're thinking of the 9mm and 40 Glocks. The 40's have larger barrel diameters, so converting to 9mm requires a conversion barrel.
No. Wouldn't have done that. I think it may have been the .40 and .45. That's all that was available/allowed at the dept. in about 92. The more I think about it, the more I remember what didn't work. There were no conversion barrels then, that we knew of, so it was all mix (mis)-matching available original parts. There was one working "conversion" at the time, and I think it was the .40 in a .45. All moot at this point, with the availability of simple conversions. I wasn't a Glock fan, at all, until about that time.
Pretty sure there are no factory Glock 40 barrels that fit in a 45 slide or frame, regardless if you used a barrel bushing. Large frame vs small frame. Not counting the 45 GAP models of course, those weren't around at that time.
The only Glock barrel conversion that would have possibly used a barrel bushing at that time would be a 9mm barrel in a 40 slide.
Some great info coming out in this thread!