thx, have a look at the code in ad0915628 - i mentionned in a previous post that i salvaged much of it. however 6dof equations of motions are not so difficult to implement. the hard thing is to get the aerodynamic coefs right,

Okay, I didn't know it was this SPINNER code you meant.. It's a shame because it could have been pretty accurate at least according to pp presentation of it. And intlift doesn't give all the coefficients but it's a good start.

First version of gyroscopic stability (SG) calculator attached.

I used intlift2 results as an external table as Robert suggested. Sheet is example calculation for Berger 70 gr. VLD bullet. Bullet mass is actually additional input value and one can use it to "SOLVE JACKET THICKNESS" by pressing a button as jacked thickness is hard to measure. Then code iterates jacket thickness until bullet mass given is equivalent with bullet mass calculated from dimensions.

I spent a while wondering what's wrong with ogive ratio. Then I realized that these ogive ratios are not equivalent with other ogive dimensios in Litz's book.