I'm shooting a 27" Xcutter shaft (7.8gpp); nock bushing (17.2gr); pin nock (2.8gr); x-vanes at 10gr ea x 3.

So......210.6 on the shaft + 17.2 + 2.8 + 30 is what's behind the tip. Tip is a 50gr. GT Glue in.

I used the GT calculator to figure the FOC.

.89