BTW, I saw pics of the tins for the big bore JSB Exacts.... The .30 cal is 46.3 gr. and the 9mm is 77.6 gr....
That puts them similar to a scaled up 25.4 gr. Exact King .25 cal.... Exactly scaled (cubed) that would be 47.5 gr. and 74.0 gr.... Of course the SD is higher with the larger calibers, so the BC should go up....
Bob