Coyote Hunter,
I don't know what ballistic program you're using, but I first used Sierra Infinity with Berger's own G1 ballistc coeffcients for both bullets. Today I ran it through the Point Mass Ballistics Solver from Bryan Litz's book, using Berger's G7 ballistic coefficient. I listed the 168 at 2850 fps, because that's what I've found to be a more realistic velocity when comparing the two bullets, if the 140 is started at 3100.
The programs didn't produce identical results, probably because of the different G1 and G7 BC's used, but they both agreed that the 168 at 2850 would catch the 140 in velocity at right around 500 yards. With both programs the difference in widn drift was about twice as much as you indicate.
Any difference in drop is irrelevant these days, what with laser rangefinders and an easy means of compensating, whether with a multi-point reticle or by twisting the elevation turret.
