I have gone to various Forums and Sites looking for a Formula or Model that I could use in the field to determine my maximum ordinate and be fairly accurate. I don't like being dependent on apps, battaries, and electronics, and would love a Mathematical Formula. I have not had any luck thus far. One guy asked for a hypothetical situation with regard to data, I gave one, but he never got back, so here is what I gave him. Caliber - .308 W Bullet - 168gr BTHP Muzzle Velocity - 2678fps Muzzle Velocity Variation - 32fps Ballistic Coefficient - 224 Sectional Density - 192~lbs/ft ^2 Target Distance - 1000yds Elevation - 1000ft Humidity - 0-10% These are the parameters the fella said he would need, but like I said he never got back to me. I suppose it would be possible for other factors to play a role on the Maximum Ordinate (MO), Spin Drift, CANT, ammo Temp etc, but this is all the guy said he would need to show me how to set up the formula and work it our. Thanks in advance, this stuff isn't easy.