A grain is a unit of weight equal to 0.002286 ounce (avoirdupois) or 0.0648 gram (metric). Arrow component weights are measured in grains.

The grain weight of a broadhead will affect several things:

1) Overall weight of the completed arrow. An arrow shaft tipped with a 125 grain broadhead will weigh more than the same shaft tipped with a 100 grain broadhead. Arrow weight affects speed, kinetic energy, and trajectory.

2) Dynamic spine of the arrow. Spine can be thought of as the stiffness of the arrow. A heavier head will make the arrow spine 'weaker' and it will flex more during flight.

3) Front of Center (F.O.C.) percentage. FOC is the measurement of the balance point of the arrow. A heavier head will make the FOC larger.

I would personally stick to a broadhead in the 100 to 125 grain class as this weight range is in the middle of the spectrum of choices and should give decent results with most bow/arrow combinations. If you want to experiment, you can try different tip weights to fine tune your system for the greatest accuracy.

HuntingNet Member since Spring 2001