I agree with Len on this.......there is no reason that you cannot achieve bullet holes with fixed broadheads that fly true and group with your field points.
Lin hit on the the Trilogy and he was right. Although they all have an impact on your accuracy and tuning of a bow, often times the straightness of the arrow itself, is overlooked. Invest in an arrow spinner and shave hours off of your broadhead tuning time. Take your spinner with the next time you buy a dozen arrows and spin each one for straightness. If the shop will not let you pick and choose from their arrows, take the un-straight ones and send them back to the manufacturer for replacement.
Straight arrows make all the difference in the world.