well seeing as how both of em use the same exact bullit 3.07 thous or 7.62mm for those of you in the metric world,,the only differance is velosity..the 30-06 holds alittle better hitting power down range..and dont drop off as fast as the 08,,but the 08 dont kick as hard,,,i dont believe there is much either of em will not dispatch quickly,in the north america's except for grizzley...might wanna go with 06 for moose also,,,by the way i shoot a 06,,,,
HERES SOME INFO:30-06 w/150grn pspat 2910fps drops 13.57 inchs at 300yards when zero at 100 yards..remaining velosity 2083,and 1445ft pounds of energy left..
308 w/same bullit is 2820 and drops 14.69 inches at 300 w/100 yard zero,,with 1344ft pounds energy left.,so you see apples and oranges gentalmen