I shoot my x-bow free-hand standing about 10' in front of the paper which is about 4 ft in front of the target.
I do my paper tuning a little different, and I am guessing everybody has their own method.
I start out about 5-ft in front of the paper and make my first tuning attempt. Then I move back to 10-ft and take another "shot at it". I keep moving back until I reach 20-ft with a bare shaft making bullet holes or very short tears in different directions using the same shaft.
For those wondering why the increments vs. just shooting from 20-ft. First, reason is I don't want to risk a severely errant arrow due initial starting points of rest (loop). Second, reason is that non-center shot arrows oscillate up/down and left/right making it harder to determine which way the rest (or loop) needs to moved. Third, it works for me.
For what it is worth.
If you are having real trouble paper tuning a X-bow (or Bow) to achieve proper center-shots there is a possibility you have a limb that is weaker than the other or twists as the X-bow (or bow) is pulled and released.
An indication is that moving the rest (or loop) by normal amounts doesn't seem to have an effect, and requires drastic amounts to finally have an effect.
Warning here: A Whisker Biscuit type rest will somewhat mask a limb problem. The Biscuit actually tries to force the arrow to come out in a straight line.
Another indication is that your arrows don't fly a straight (left/right) path with normal downward trajectory. Instead your arrows fly like a stunt plane doing barrel rolls. On slow bows ( < 300fps ) you can see the eradicate arrow flight. A better method is to capture the arrows flight with a camera at night with a lighted knock.
The result of limb problems: You to have to set your sight pins to the left of where they should be at xx-yards and to right at zz-yards. Along with, distances between sight pins being unusually close together between xx & zz yards and way to far apart at zz & ww yards.
For a Bow, you can use a "draw board" to determine if one limb is weaker than another.
Cam positioning at draw vs. rest is another way, although I feel it is to prone to visual error (eye alignment, reference point, cam marks).
Anyway, it is difficult to determine if one limb is twisting and causing it's Cam to lean, change position up or down for X-bow (left or right for Bow) when pulled back (at draw) vs. released (at rest). Based on
non-PSE experience with a Bow, even a factory trained technician and a bow shop pro can miss the small amount of lean that results in left or right string movement upon release - making center-shot / paper-tuning impossible. On an X-bow the twisting limb would translate into up or down string movement.
