most of them, a 120gr 6.5mm would have a bc and sectional densitt that compares to about a 168gr 30cal. A 140grain would be more like a 180grain, and a 160gr 6.5mm bullet, would be comparative to that of a 200 grain 30cal bullet.
to calculate a SD, take bullet weight in lbs divided by dia squared.
You seem to disagree and then agree with my point of view.
You made a statement that was incorrect ( action ) and I corrected it for you.
Now the benefits of if a 260remington or a 6.5x47 lapua and a 160grain bullet, is another thread or posting.