from personal experience I can assure you that the heavier bullets are less effected by wind. The reason is inertia. Among the big factors in trajectory is inertia. The heavier bullets don' t deaccelerate as fast as the light bullets ...all of which suffer serious air resistance to their frontal path. Deflection due to wind is also related to inertia and heavier bullets are less deflected.......remember this all happens in less than a second. Inertia is resistance to change and the heavier bullets are better at it than light ones. I' ve witnessed this on many prairie dog towns!!!

Extreme example....the 16" guns of Naval gun boats shot about 2,200 feet/sec as I recall...yet they shot 22 miles inland with superb accuracy. Will a .30-30 do that?