I would have to say your bow is not tuned well enough, especially if the mechanicals do not group with the field tips. It may be shooting bulletholes in paper, but that is just the start.

I believe all bows are capable of getting close with the impact of fixed blades and field tips. Go to the following link and download eastons tuning guide, and follow the directions. You will have your bow tuned in no time.

http://www.eastonarchery.com/tech_room/

Or, it could be the arrows are not spined right.