I have two bows(I will not name so no bashing can be done). Both are set at 70#. Both IBO speeds are around 305fps. Both bows are the same draw length. I can tune one with a 350gr. arrow to a perfect bullet hole and get 284fps. The other bow I get 274fps with the same arrow. The problem is with the later bow(274fps) I can not get a bullet hole. I get tear left(weak spine). I then use a 370gr. arrow and then I get a bullet hole at 268fps. The 350gr. arrow is 26.5 inches the 370gr. arrow is 28 inches. Is it just the way the bows tune or is there anything I can do or try to get both to shoot the same arrow. I have tried everything I know to get the second bow to shoot through paper without throwing off the center shot. I could turn down the poundage but I don't want to if at all possible. Any and all help will be appreciated. Thanks. Bow one is 35.5ATA the second is 34ATA.