I have the the project x 5.5 and I like them a lot . I have found for me the ball flight is a lot higher than my old project x shafts

Related question: I am just getting back into the game after a multi-year absence. My irons are png i5s which I bought new around 12-years ago and plan to continue using for the time being. They are shafted with Rifle 5.5 FCM shafts, which I note are no longer available.

When I got these clubs (from RI clubmaker Tom Spargo) he told me that the 5.5 was a strong R-flex, rather than a S-flex, which I found to be true when playing them.

Are the Project X 5.5 shafts the same thing under a different name? If not, what would be the closest shaft to my Rifle 5.5s?

This is my first post, by the way and happy to be on Team Titleist (other clubs in my bag are Titleists, including a Cameron Newport from 1997).