To set-up Ontarget2 properly you have to weigh one of your arrows and also get it chronographed. Then, adjust your IBOto correct the velocity.The factory tests the IBO with thestring naked.You have to treat your IBO as if you have a bunch of things on the string/cables. Which you do.

My arrow weighed exactly what the program said it does.

To give you a ballpark for that arrow. I use 125 gr tips with a 28.25" arrow. I have a '07 Bowtech Allegiance and at 72 lbs w/ a 30" DL I chrono'd 293 fps.