I finally was able to acquire a new recoil spring for my CS9. I always like to replace the recoil spring whenever I pick up a used pistol.
I've attached a picture that shows the old spring on top and the new spring on the bottom (9mm round for scale).
I had no idea the new spring would be that much longer. I have read that new springs will take a 'set' and get shorter but I was surprised at the difference in spring length - new vs old.
I'm thinking the old spring must have seen a lot of rounds?