It sounds like you either need to lower your nocking point or raise your rest a bit depending on where it currently is.
Good advice, provided your field points are grouping good, and your broadheads are grouping good. If your broadheads won't group, but your field points do, you need to make sure your bow is tuned correctly, and your using the right arrows (length and spine). Sure like how those 50 cals sight in though!