rybohunter

OK you have 2 bows set at identical draw length, weight, and similar cams. One is and older bow, lesser technology, kicking the arrow out fairly slow. The other is a newer model, kicking the arrow out significantly quicker.
How is it that the 2 bows can shoot the same arrows according to the charts when arrow speed is different? Wouldn't the faster bow be putting more force on the arrow? Or does this fall into the reason why there are several choices or arrow size for one setup?

Rack-attack

Thats why there is a cam selection on the right of the better Easton charts. It helps compensate for the speed factor diff. between bows.

98Redline

The the arrow selection chart is really just an approximation of the arrow that will spine best for your bow. Picking the correct cam on the chart will get you closer but most likely not right on the money.

Programs like Archers Advantage, and TAP factor things like the efficency of a specific bow, draw weight, draw length and actual poundage into the equation to come up with the best match of spine to the bow.

In most cases, if you are off a little on spine (stiff or weak) you will be ok. You can also "tune" your arrow setup by changing point weight or changing the draw weight of the bow to put you right in the sweet spot for your selected arrow.