Take a look at the exterior ballistics chart above.
You'll see some interesting things happening downrange.
The relatively light and fast 70 grain bullet gets out of the gate fast, but drops as the lighter bullet loses steam downrange.
The heavier/slower 100 grain drops about the same amount because more energy and thus momentum is retained with the heavier bullet.
One could get a compensator dial setup for the 70 grain, and with practice take chucks at 500 yards.
That same dial would put him within a couple of inches of point of aim on whitetail deer at extended ranges.
There is, of course, a lot more to long range shooting than turning a dial. Windage must be read and adjusted for. Cant must be eliminated.
And lots of practice will build the confidence to know when to shoot and when to get closer.
By the way, the above data is from Federals Ballistics program and can be downloaded from their site.
You can plug in wind speeds, elevations, etc. and tweak your loads to suit your situations.