I shoot a switchback with a 26.5 draw, set at 65 lbs, 25 inch carbon express maxima 250 arrows with 85 grain tips. The arrow alone weighs 7.3 grains per inch. The matthews book says that you should shoot an arrow that weighs 5 grains of arrow per pound, or you are simply dry firing your bow. I don't have a scale to weigh my arrows, does anyone know if this is an ok setup??? An archery shop told me that's what i needed??