ORIGINAL: ipscshooter
Part of the preference might be related to the fact that there are a wider range of factory loads for the .30-06, from 55 gr.up to 220 gr., whereas I think the largest bullet you can get in a factory load for the .308 is a 180 gr.
According to my handi dandy ballistic chart you are right there are lot more bullet weights for the 06.. But the 308 ranges from 110 - 200 grains.. But you don't hear of an 06 for a varmit weapon or target gun. Where you do as a 308????