RE: Powder measure/working up a load
Greenhill Formula that, while it was designed for estimating twists for boat tailed lead core bullets of moderate velocity, does a pretty good job of estimating twist required for flat based bullets under "normal" conditions.
T = Twist in inches
K = Greenhill's constant = 150 (This has to do with the specific gravity of a jacketed lead bullet)
D = Bullet diameter in inches
L = Bullet length in inches
T = (K * D2) / L
[K = Greenhill's constant = 150 X Dia. X Dia.] divide by length of bullet.
There are free ware programs available which make it real simple I have one I picked up some where. Lee