CM9 recoil springs

[deadeye]

Would like to get a Wolff recoil spring set for my CM9 but they don't list them as such. Am I correct in remembering the PM9 is the same set?
Which is recommended the 18 or 20# set? Thanks for your help.

[DavidR]

Yes, same as PM9. 18# is stock. 20# is heavier, possibly better if you shoot +p.