I had the same problems when sighting in my BHs, they were hitting low and to the left from where my field points hit. After fiddling around with paper tuning, adjusting the rest, knock point and sights, the answer came when I changed arrows to a stiffer spine and better quality arrow. Now my BH and field points fly together.
Stay away from the Walmart specials, even their most expensive arrows are a piece of junk. Guess you get what you pay for. Now I'm shooting Carbon Express Maxima Hunters, 350s for a 67 pound bow.
I won't be changing arrows any time soon as I recount the numereous hours wasted trying to tune around bad arrows.