My broadhead and insert weighs around 210 grains, the vanes and lacquer spray/glue around 20 total, the nock is 21 and raw bolt about 146 grs for a total of 395 grs. The center of gravity for my vanes is 1.75" to the rear of the shaft.
I used this: http://www.goldtip.com/calculators/foc.asp to calculate my FOC.