Nomercy448

Just a bit of clarification to make here:

Draw weight and draw length, or more accurately, the bow's drawstroke "power curve" or "force curve", determines the Potential Energy stored in the bow. Upon firing, this Potential Energy is converted to Kinetic Energy imparted to the arrow. So yes, draw weight and length DO determine the Kinetic Energy that a bow can put out. But you do need to know the cam factor for the bow.

You can actually determine a bow's relative power (some guys call it cam efficiency, which is wrong), or cam aggression by measuring the draw weight at each inch of a drawstroke, plotting it on a page, cutting out the square of paper, weighing it, then cutting off the area above the curve and weighing that. Most bows fall somewhere between 45-65% of their maximum theoretical potential (peak draw in pounds x draw length minus brace height in feet). More aggressive cams and shorter valley bows usually higher percentage than easier drawing, more forgiving cams. Yes, the release does lose some energy to friction and arrow flexion (and heat and sound), so the drawstroke potential energy is always slightly more than the arrow's KE, but not significantly different. In a direct sense, this means I can take two bow brands, put them on a draw board, NEVER FIRE A SHOT, and tell you which one will be faster with the same arrow.

So in a very real sense, yes, the draw weight and draw length, which determines the Potential Energy stored in the bow, does indeed determine the Kinetic Energy imparted to the arrow.