# Heavier recoil spring needed? G20 Gen4 + 9x25 Dillon



## Mister_Torgue (Sep 14, 2018)

Greetings all.

I'm about to pickup a Glock 20 Gen4 with my yearly bonus money with the plan of converting it to 9x25 Dillon. Already have a 9x25 barrel (4.6") in preparation for this conversion.

My question revolves around whether or not I'll need a heavier recoil spring (or metal guide rod)? I'll also want to run hotter 10mm loads so my thinking is I'll need more than a 17# recoil spring. Does this make sense to you all? It's my first Glock and I have zero idea how the platform behaves. I'm more of a steel frame / milsurp guy just now buying polymer. 

If it is a good idea to upgrade to a heavier spring what are your thoughts on this one below (20#)? And help is appreciated!!

https://www.glockmeister.com/Glockm...-Gen-4-20-21-40-41/productinfo/G4SS20CS/9807/


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## denner12 (Oct 14, 2017)

Why not, as long as the pistol functions reliably. I run a 20# ISMI flat spring in my Gen 3 G-22 rated for 1,00000 cycles or one year and a stainless guide rod from Brass Stacker. A 17# spring running hot 10mm seems a little on the light side for my liking, but to each their own. Do you need to, no, but it's your call. Any .40's I've run are reliable in my pistol, the 20# spring is a little tight at first but wears in nicely, probably will never need to change it.


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## tjkarch60 (Jul 14, 2017)

I have a Gen 4 G20 and handload. My loads aren't super hot, and downloaded a little from the max recommended loads. What I would like to know what spring weight would be the best? Is 20# enough, or is 22# better? I also have a Lone Wolf 40 S&W barrel and can use the stock 17# for that.


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## Mister_Torgue (Sep 14, 2018)

denner12 said:


> Why not, as long as the pistol functions reliably. I run a 20# ISMI flat spring in my Gen 3 G-22 rated for 1,00000 cycles or one year and a stainless guide rod from Brass Stacker. A 17# spring running hot 10mm seems a little on the light side for my liking, but to each their own. Do you need to, no, but it's your call. Any .40's I've run are reliable in my pistol, the 20# spring is a little tight at first but wears in nicely, probably will never need to change it.


Good to know. Thanks for the reply! I'll get a 20# spring just in case. Better to have than not have.


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## Mister_Torgue (Sep 14, 2018)

tjkarch60 said:


> I have a Gen 4 G20 and handload. My loads aren't super hot, and downloaded a little from the max recommended loads. What I would like to know what spring weight would be the best? Is 20# enough, or is 22# better? I also have a Lone Wolf 40 S&W barrel and can use the stock 17# for that.


From what I read a 20# should be good but that's why I posted here. I wasn't 100% sure. I think the 17# factory spring just may not cut it.


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## denner12 (Oct 14, 2017)

tjkarch60 said:


> I have a Gen 4 G20 and handload. My loads aren't super hot, and downloaded a little from the max recommended loads. What I would like to know what spring weight would be the best? Is 20# enough, or is 22# better? I also have a Lone Wolf 40 S&W barrel and can use the stock 17# for that.


I'd run a 20# spring and see how that works for you, that would seem about optimal for your application. A 22# spring is a lot of spring but some run those as well. You would need to see which runs best for you and to see how far the brass is being kicked out and/or for any reliability issues. I run a #20 spring in a G-22, so you know my thoughts on the matter.


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## tjkarch60 (Jul 14, 2017)

denner12 said:


> I'd run a 20# spring and see how that works for you, that would seem about optimal for your application. A 22# spring is a lot of spring but some run those as well. You would need to see which runs best for you and to see how far the brass is being kicked out and/or for any reliability issues. I run a #20 spring in a G-22, so you know my thoughts on the matter.


Thank You, I think I'll try the 20#, It should be good.


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