Glock Conversion

[Lokpyrite]

Howdy Folks.

I know that you can get a new barrel and magazine for a Glock 40cal to convert it to 9mm, and I think it's possible to go the other direction(but not sure). But is it possible to change a G21 from 45acp to 10mm by just switching barrel and mags or do I need a whole new slide?

 

[Marco Califo]

Glock factory barrels

In some cases, you can convert down. Never convert up. See the barrel descriptions. If they do not say you can do it, then you can't. You CANNOT convert 9mm to 40. You can convert 40 to 9mm.

Other than Glock factory barrels, I do not know.

http://www.glockmeister.com/G20-GLOCK-Factory-Barrel/productinfo/G5355/

This is the factory Glock 10mm barrel that comes stock in the Glock model 20 and 20SF. It can also be used to convert the 20C to shoot as a non-compensated. Using it to convert the 21 or 21SF to shoot 10mm is not recommended and unsafe as it is not a 100% fit. This barrel will not work extended in the 29 or 29SF due to the difference in the locking blocks.

This is the factory Glock .45 barrel that comes stock in the Glock model 21 and 21SF. It can also be used to convert the 21C to shoot as a non-compensated. Using it to convert the 20 or 20SF to shoot .45 ACP is not recommended and unsafe as it is not a 100% fit. This barrel will not work extended in the 30 or 30SF due to the difference in the locking blocks.

 

[sigxder]

Going from the larger gun to the smaller one is usually fairly easy. They just use the same sized barrel as they would for a .40 but only bore it to 9mm or say .357 SIG. The the .40's barrel is too big in diameter to use in a slide cut for 9mm. Some guns can convert between .40 and 10mm. Some .45's can accept .400 Cor Bon or .45 Super barrels. But not too sure about the springs on these conversions.

 

[Marco Califo]

WHAT?

Going from the larger gun to the smaller one is usually fairly easy. They just use the same sized barrel as they would for a .40 but only bore it to 9mm or say .357 SIG. The the .40's barrel is too big in diameter to use in a slide cut for 9mm. Some guns can convert between .40 and 10mm. Some .45's can accept .400 Cor Bon or .45 Super barrels. But not too sure about the springs on these conversions.

I take it you are NOT referring to Glock factory barrels, which will ONLY drop in under certain specific instances, and may or may not, use different magazines (40/357 for example). Since you are not referring to Glock factory barrels, please state which manufacturers' after-market barrels you are referring to, and ideally, reference their website and product information. Thx.

 

[ET.]

Yes you can convert the Glock 21 to 10mm with a barrel conversion. KKM makes a 10mm conversion barrel that drops into the Glock 21. You only need the Glock 20 mags. I'm getting ready to buy one and was told that I need a 10mm ejector as well. I intend to buy the ejector but I've been told that some people are running this barrel with the 45acp ejector with no problems. I still think I will change out the ejector, which is an easy task anyway.

I bought a +p recoil spring for my G21 last year, but never installed it since it won't reliably cycle standard pressure 45acp. I think I will install it when I install the 10mm barrel & ejector since the 10mm rounds are a higher pressure round than the 45acp rounds. This isn't necessary but heck, since I'm sitting on this $100 recoil spring I might as well use it.

 

[207Copper]

Glock

I know they make it but I say good luck. I did the barrel conversion LWD for my G22 40-9 and then couldn't hit the side of a barn with it. Sold it and went back to the factory setup. Could have been a fluke but thats my experiance.

Jason

 

[ET.]

I've been running a 40-9 conversion barrel on my Glock 27 for 2 years now & about 2000 rounds. The accuracy is as good as the OEM barrel. It might be that the shorter barrel in the 27 isn't exactly a tack driver to begin with. But as you say, each barrel & each gun are different. I have one that mirrors the OEM barrel , you seemed to have had one that didn't. With my luck I would have bet the opposite. Glad I don't bet... at least that's the line I use at Gamblers Anomynous.

 

[Desertscout1]

You can use a stock, G20 10mm barrel in a G21 or a G21SF. If you want to use a "conversion" bbl, that's cool too but it is unnecessary. The ejector will work fine but on some guns, you may need to change the extractor. Jason has been carrying and shooting a G21SF with a stock 10mm bbl without any other changes at all with 100% reliability for about 3 years.

 

[Marco Califo]

You can use a stock, G20 10mm barrel in a G21 or a G21SF. If you want to use a "conversion" bbl, that's cool too but it is unnecessary. The ejector will work fine but on some guns, you may need to change the extractor. Jason has been carrying and shooting a G21SF with a stock 10mm bbl without any other changes at all with 100% reliability for about 3 years.

Not according to Glockmeister.com which sells that barrel:

"This is the factory Glock 10mm barrel that comes stock in the Glock model 20 and 20SF. It can also be used to convert the 20C to shoot as a non-compensated. Using it to convert the 21 or 21SF to shoot 10mm is not recommended and unsafe as it is not a 100% fit. This barrel will not work extended in the 29 or 29SF due to the difference in the locking blocks."

 

[Desertscout1]

Not according to Glockmeister.com which sells that barrel:

That's because they sell the barrels. We actually do it AND use and shoot the guns.

 

[Marco Califo]

That's because they sell the barrels. We actually do it AND use and shoot the guns.

You are recommending ignoring the factory warning not to do this because it is unsafe. Do you have any documentation from Glock saying this is safe to do?

You do not.

Just because you have done it, and not blown up your gun yet, does not refute the factory recommendation. IMO that is an irresponsible post here.

 

[Desertscout1]

You can think whatever you want dude. Means nothing to me. Some people can think outside the box and some can't. If you seem to think that everything needs a factory blessing, that's OK with me. I do this for living and have for quite a few years.