Sighting in a 300 Win mag at 50 yards is like putting rabbit ears on a new TV...I'd go with 2 1/2 high at 100...This should put you close to dead on at 150 and probably 3-4 inches low at 300....I always check my gun at 50, 100, 200, 250 and 300...Ballistic tables give you a rough idea...But I have found them not to be exact...Two different guns shooting the same loading will have different velocities...