What nobody has told you yet is that 5 grains per pound is what most manufacturers warrant as the MINIMUM arrow weight for the bow. Even though most guys want to take it as such, 5 gpp is NOT a recommended arrow weight. 5 gpp is nothing more than the lightest arrow you can shoot out of your bow and then be able to get the bow fixed under warranty if it breaks.

The way I do things is to use light arrows (@ 6 gpp) for 3D, where I need to shoot unknown distances out to 50 yards and the speed and flatter trajectory will mean more points on my scorecard. I do not need power for deep penetration on targets and, acutally, I want to limit penetration on the targets to make my arrows easier to pull!

For hunting, where my shots will be less - usually MUCH less - than 30 yards, I don't need that flat trajectory. I need POWER to punch the arrow through the animal's ribcage. So, I use substantially heavier arrows (10-11 gpp) for increased energy and momentum. Not to mention better accuracy, as well as the easier tuning Bees is referring to.

The high speed and super flat trajectory I needed for long range target shooting is not an overpowering requirement for hunting. I go by the old rule "for hunting, use the heaviest arrow that will give you ACCEPTABLE trajectory." The power I need for hunting is not a requirement for target shooting. So, I match my arrow weight to the task at hand.

If you don't want to swap back and forth like I do, then use a medium arrow weight, balancing the speed and trajectory with penetrating power for ALL your shooting.