T2013 STAGE III Ballistics Calculation Question

[3catcircus]

So,

I'm going through and statting up some new weapons and ammo. Stuff like the S&W M&P 10 or the LSA TX15. These are using 6.5 Creedmoor or 6 ARC.

While I could just say that these are equivalent to the 6.5 Grendel, my intellectual curiosity demands that I figure out Stage III ballistics values for them.

Anyone know how Stage III ballistics are calculated? The math doesn't scare me, I just need to understand how the formulas vary in each range band.