Sounds right to me.

Your exact trajectory will depend on your gun, and things such as the height of your scope in relation to the bore. A basic rule of thumb is to sight in dead on at 25 yds. This will place most trajectories on the paper at 100 yds. Verify your trajectory at 100, adjust as necessary, and then verify at longer ranges, and make further adjustments as needed to establish your maximum point blank range (MPBR).

MPBR is the distance to which you do not need to adjust your point of aim. With a 308 that may be 225-250 yds. Within that range you aim dead on and shoot. The bullet will hit anywhere from 2-3" high to 2-3" low of your point of aim. If you hold dead center, that's a dead deer every time.