Hi Team Titleist, When recently hitting a friends Ap1 712 6 iron with x 300 s shaft, it has a noticeable click sound at impact( which I like ), my Ap1 712 irons with NS PRO 950 s shafts don't seam to make the same impact sound . Is this due to the shafts ??. I remember hearing the " click "at the pro shop when origionally trying my irons as well.Hope you can enlighten me. Regards Adrian F