Shaft FCM estimate

[GeoffDickson]

Club: Callaway X-16 Pro series
Shaft: Callaway constant weight rifle steel Tour X-stiff

Question: What would the likely FCM be? 6.5?

 

[otto6457]

Since no one has answered I'll jump in and seek education.

What the heck is FCM?

 

[softconsult]

Stands for Frequency Matched. The C, may be Calibration, or Coefficient depending on the internet source.
Google will give you more info than you ever wanted.