i guess i would have to try tuning the bow with the broadheads on despite what any literature said. i haven't found a head yet that hits exactly where my fp's do when optimally tuned. dial in at 20 yds, then back up to 30 and still use your 20 yd pin and aim at the same spot. your arrow should fall directly below, in a vertical line, the one you shot at 20. if your arrows are off left at 30 the arrow rest needs to go to the right, and vice versa. i guess this could also be caused by porposeing. do you have bad nock travel? you could also shoot a horizontal line across your target, if your group varies up and down by an inch or more from 20 yds you could try taking a little off of your bottom limb, like 1/8 of a turn, and see if that fixes it. i shoot blazer's and prefer to put a helical on them, specially for broadheads. i really don't think going no offset, so your arrow is not spinning, will do anything but magnify issues, but i'm wrong lots.