In the conditions listed above where a 223/80 is drifting a foot at 250 yards, a 243 with 105s (either 105 Amax or VLDs) is drifting around 10-11”. Either one would require a wind call to be made. Of course one could fart around with max loading one and handicapping the other and skew numbers as one sees fit.
A 75 eldm at 2850, in typical Eastern Montana fall conditions, will drift a foot at 250 in a 29 mph wind. Not sure what 75 you’re using to come up with your numbers. I’m betting it’s a guess.
