I thought there was a topic on this earlier but couldn't find it using my weak search skills.

   I recently completed building a G21 and will eventually buy a G-20 barrel but am not certain which recoil spring to use (Glock part numbers for the spring appear to be the same for both models).

   To my uneducated mind it would seem a different/heavier spring for the 10mm as I would mostly shoot true 10mm loads.

Thanks,
John

When I was running 45 Super through my G21 I used a 24# Wolff and kept in for full power 10 and everything ran fine.

Thanks- I'll look for the 24# spring.

Both a factory G21 and G20 use the same factory spring. Back when I ran a 10mm conversion barrel in a G21 I used the factory spring and it ran great.

 This.

It's the same part.

I swapped barrels on my G41 from .45 to 10mm.....runs fine with the stock recoil spring