ok, everybody else i've read says their magnus broadheads hit the same place as their field points. mine are hitting six inches low and right at twenty yards and farther off at thirty. im shooting a 70 lb pse rogue, 28.5 in draw with beman 340 arrows. not sure how fast the arrows are moving, shooting 125 grain stingers. any ideas as to what i'm doing wrong? thanks for any help.