I recently purchased a cronograph from Sinclair a CDM2,took it to the range today 47degrees,shot some loads out of my 300 win mag 81grs of h-1000,78.0grs of imr7828ssc and 73grs of I-4831 all behind a 180gr bullet the velocities were as follows 2731-2739 for h-1000,2863-2866 for i-7828,&2766 for...