fritz, remember to add 15 grains for the insert, 15 grains for the lock nocks, and then the weight of your feathers. I had a friend who kept telling me that it was impossible for him to get a heavy enough arrow, but he wasn't add the fletchings, insert, and nock weight to his total.
For instance, my new GoldTip 3-D Pro 75/95
28.25" X 8.9 grains per inch = 251.425
251.425 grains + nock weight (15 grains) = 266.425
266.425 grains + insert weight (15 grains) = 281.425
281.425 grains + vanes weight (8grains X 3 vanes = 24 grains) = 305.425
305.425 grains + tip weight (100 grains) = 405.425 grains total weight
According to my calculations, that arrow should fly out of my bow at about 275 f.p.s. which will give me around 68 ft-lbs of KE
