Bow Tuning Calculator

A true bullet hole is a single round hole with virtually no elongation, but real paper tests almost always show a sliver of tear from fletching contact even on a well-tuned bow. The calculator treats any tear under a quarter inch, or any tear when Tear Direction is set to Center, as effectively tuned and reports no adjustment needed with a low Tune Score, because a correction at that scale sits inside normal shooting variance rather than a genuine spine or rest timing problem worth chasing.

Tune Score scales directly with the tear size you measure: a bullet-hole result multiplies that length by a small factor, while any directional tear multiplies it by a noticeably larger factor to reflect that a directional tear is a real timing problem rather than fletching-contact noise. A bigger tear at the same reported size therefore always produces a higher score, so it works as a rough severity ranking for deciding how urgently to act and roughly how large a first correction to try.

Rest type mainly changes which physical adjustment is available for a high or low tear: a drop-away rest lets you raise or lower the rest itself as a secondary correction, while a whisker biscuit or blade/lizard-tongue rest is typically left fixed and corrected through nock point height alone. For left or right tears the horizontal centershot recommendation is the same regardless of rest type, since side-to-side rest adjustment works the same way across common rest designs.

No — standard paper-tuning practice is to make one small adjustment at a time, re-shoot through a fresh sheet of paper, and re-read the resulting tear before making another change. Adjusting the rest and nock point simultaneously makes it hard to tell which change actually fixed or worsened the tear, and can also overshoot past a true bullet hole in the opposite direction, so treat each recommendation as one incremental step rather than a single final fix.