For hunting, you want a broadhead that will give you a Front of Center (F.O.C.) percentage between 10-15%. You wouldn't want a broadhead that would cause F.O.C. to be over 15%. With that in mind, I present the following courtesy of Larry Wise in his book Tuning and Silencing Your Bowhunting Shooting System:

P = (.5N + 2F - A(N+F)(.5+R)- RAW) / ((R-.5)A + 1))

where:

A = total arrow length including point and nock
F = total weight of fletching in grains
N = weight of nock in grains
P = point weight in grains
R = F.O.C. percent in decimal form
W = total shaft weight without nock, fletching or point

For your calculation, set R = .15 and input your own weights and lengths. Doing a little algebra will give you a P value that will be the maximum point weight you should consider. This may not be the best broadhead weight for your particular setup, however. The truth must be found though group testing using various point weights.

Personally, if I was looking for a relatively heavy broadhead on my carbons I would forget the formula and just try something in the 125 gr. class: lots of brand and style choices in this weight.



HuntingNet Member since Spring 2001