I use this spring, it works fine. The second stage is adjustable to 500/550 grams (1.102/1.212 lbs).
https://www.leespring.com/compression-springs?search=LC016A02S316
I like the straight and two-stage trigger.
I changed the spring, set the second stage to 500/550 grams (1.102/1.212 lbs).
https://www.leespring.com/compression-springs?search=LC016A02S316