Something as simple as this would be IMO quite useful;
With the 2.5x20mm scope, hash marks from top to bottom (ranges for the Speer 75 GD load from a 16-inch barrel, 200 yard zero);
- 8 MOA (430 yards)
- 16 MOA (600 yards)
- 24 MOA (725 yards)
^ 32 MOA - top of post (825 yards)
With the FX III 6x42mm, those marks become much more useful;
- 3.5 MOA (300 yards)
- 7 MOA (420 yards)
- 10.5 MOA (480 yards)
^ 14 MOA - top of post (550 yards)
Without the hash marks, visually dividing the space between the center cross hair and the top of the bottom post is not terribly difficult but the smallest error with the 2.5x results in substantial hold-over miscalculation. The hold-over estimation with the 6x scope IMO becomes
much more doable as the total drop from center to the top of the bottom post is 78 inches vs. 274 inches (nearly 23 feet) with the 2.5x.
Additionally, 550 yards is about as far as I'd want to take a shot with this rifle anyway.