The SSR is a well balanced weapon and mine came from the factory with a great trigger and the mainspring has the same rib on it that the wolf springs come with. Never tested the trigger pull weight on it but it's very light for a factory gun. I did have to put the 1mm longer firing pin in to compensate for fail to fires with a light firing pin strike. I'm sure I could have put in a stronger mainspring but the extended firing pin seems to have corrected the issue.