Setting up Glock 21 for .45 Super

[Buzznrose]

Right now, I have a G20 and G21 (both Gen 4’s). I shoot the 21 much more and really like the gun. The G21 has approximately 4,000 rounds through it.

I want to make the gun fully capable of shooting .45 Super occasionally (50-100 rounds max per year). I’ve read it’s pretty safe to shoot out of the box, but I want to hedge my bets.

I’m thinking about a heavier recoil spring and maybe a new barrel (KKM). Not sure if this really enough to prevent damage or become unsafe.

Another option I’ve considered is just getting the Roland 460 conversion, but I really don’t want to increase the length of the gun with the extended barrel or comp.

If you have suggestions for modifications, I’d appreciate a link to the item if possible.

Recommendations to replace the gun with an HK or whatever else not wanted, nor are recommendations to stick with 10MM. My G20 isn’t going anywhere, but it doesn’t see a quarter of the rounds my .45 does.

Thank you in advance.

 

[Richard Jay King]

I really do not know how the myth of the super heavy recoil spring for .45 supers got started...If you do all the math the mass of the slide/barrel combo has waaaaay more to do with the slide impact energy on recoil than the recoil spring does...like 10 to 1! I shoot Super in my Smith and Wesson 4506 and I use an 18 lb spring which is only one pound more than the stock spring. The mass of my barrel/slide is 0.583 kilograms so if the barrel/slide of your Glock is close you should have no issues at all as is. I do not know if the Glock has a fully suppoted chamber though so I would make sure of that before I shot any Super loads.

 

[Dan-O]

I wouldn’t dare shoot 21 super from a gen 3 or prior stock barrel. Don’t know how the support is on the gen 4’s.

you might be ok with the stock rsa since they switched to the double spring in the 4’s

i think buffalo bore used to give info on their site about .45 super. I’m too lazy to look for you

 

[Buzznrose]

I really do not know how the myth of the super heavy recoil spring for .45 supers got started...If you do all the math the mass of the slide/barrel combo has waaaaay more to do with the slide impact energy on recoil than the recoil spring does...like 10 to 1! I shoot Super in my Smith and Wesson 4506 and I use an 18 lb spring which is only one pound more than the stock spring. The mass of my barrel/slide is 0.583 kilograms so if the barrel/slide of your Glock is close you should have no issues at all as is. I do not know if the Glock has a fully suppoted chamber though so I would make sure of that before I shot any Super loads.

I understand. Thank you. I know the Rolinator would be much more effective at mitigating the recoil than a heavy recoil spring...I am just wondering if I actually need it based on the amount of shooting I plan to do.

Some options I’m considering are the 460R 24# recoil spring and, if necessary, the weighted rear sight:

https://www.460rowland.com/shop/extras/the-rowlanator/


https://www.460rowland.com/shop/extras/glock-21-recoil-spring-assembly/

 

[Buzznrose]

I wouldn’t dare shoot 21 super from a gen 3 or prior stock barrel. Don’t know how the support is on the gen 4’s.

you might be ok with the stock rsa since they switched to the double spring in the 4’s

i think buffalo bore used to give info on their site about .45 super. I’m too lazy to look for you

Thank you!

I thought so too but could not find info on the BB site.

I did find this article by Larry Mudgett...it has some good info I’m considering...

http://www.marksmanshipmatters.com/comparing-the-10-mm-450-smc-and-45-super-for-predator-defense/

I also sent an email to Glock to confirm if the Gen 4 barrels are fully supported. I believe they are, but would like to know for aure

 

[Richard Jay King]

The difference in slide energy between a .45 acp with a 200 grain bullet at 900 fps vs the same bullet in a Super at 1200 fps is almost double everything being equal..So the gun WILL take a greater beating shooting Super no matter what you do....Will it break the gun a 100 rounds? 1000 rounds? 10,000 rounds? I have no idea. I do not worry because I hunt with my Super and rarely shoot over 20-30 Super rounds per year with most of my practice shooting .45 ACP. The fact that hot loaded 10mm's have an almost identical recoil impulse says that Super shooters can expect similar life to the 10mm versions of the same gun.

 

[5-SHOTS]

I'd replace the recoil spring with a +4lbs if it exists and a new stronger take down piece (if it exists...) which is the part that gets hammered when the slide returns forward.