Had a strange experience at the range today. Working up drop charts for my 6.5x.284. Berger 140 gr. 2930 fps through them chrono during load work up, no chrono today. Shot a golf ball sized rock at 100 yards to verify zero. Target at 500 yards. Dialed in 8.5 minutes from my iPhone ballistics app. Shot high. Dialed down to 7.5 MOA Shot high Dialed down to 6.5 MOA Perfect elevation. 3 inches to the left due to wind. Compensated and the next two were 1/2" apart. My deer rifle really shoots. My question is, to get the drops correct the velocity needs to be 3250 fps. I have never had to change my velocity this much. Anybody else seen this?