Home Forums Hunting & Shooting Bowhunting Tuning for "heavier than normal" spine

A quick search finds the Stu Miller calc here: http://www.taylortel.net/~rickbarb/dynamic_spine_calculator.html

Oddly enough, it has a few errors someplace:
- It does not recognize (gives error for) Beman Centershot 340 spine shafts.
- For Beman Centershot 400 and 500 shafts shows the ID to be 0.201 instead of 0.231". And recommeds, therefore, the wrong inserts.

Entering same data into both calculators yields excactly the same dynamic spine for my Bob Lee. For the arrow, the two calcuators differ by about 2.5. Hard to say which is more accurate. I note that both allow for "calibration" for my "form". In the end, I think they both give you a good starting point to set up your arrow and tune till it flies well.