Why does my bow shoot to the right or to the left?
This question can be answered as simply as checking to see if the bow is being cocked off center. If the string is cocked off center to the left or right, the arrow will shoot off to the left or right. The string being off center by as little as 1/8" could result in the shot being off several inches down range. To remedy this, put a mark on the string's center serving where it crosses over the flight track when the bow is not cocked. When you cock the bow to shoot again, make it a priority to have the string's marks centered in the trigger mechanism. If it is cocked and still off center, grasp the string and nudge it into the centered position, with the safety still engaged.
The other problem may be slightly more technical. Your bow could be out of till (out of square). If you have made any adjustments to the limb bolts (the bolts that secure the limbs onto the bow) this is a possibility. To accurately measure your tiller, begin from the point where the limb meets the prod housing back to the string. Do this on each side of the prod housing. If the measurement is not equal then the bow is out of till. It would be best to have a dealer make the till adjustment to correct the problem. All Barnett Compound Crossbows are pre-set for tiller and proper draw weight at the factory.