OK here goes I am currently shooting carbon Hawks by beeman 400 series cut to 29 inches and 125 grain mech heads out of a darton yukon XT set at 63 pounds and a 27 inch draw is my spine ok now and what will happen if I drop down to a 75 grain fixed head I did shoot some 75 grain field points through paper and I am getting a nice bullet hole HEY FIVE SHOOT YOU OUT THEIR