Free: Contests & Raffles.
the 180's have aprox 200 more ft lbs of KE at 500 yards . the 165's 1.3 at 100 and -17 at 400 . the 180's 1.5 at 100 and -19 at 400 at 500 yards the 165's drop 39 and the 180's drop 38 . so past 500 i'd go with the 180's better bc and energy.
Since you are dialing the scope trajectory doesn't matter how flat it.shoots. you dial in anyways to what your rangefinder says. Higher BC and heavier bullet will be les affected by wind.