The .308 case, no matter how much you "improve" it does not hold enough powder to get heavy 9.3 bullets such as 286 grains, going fast enough. You are limited to about 50 grains of powder. Once you go to a decent weight 9.3 bullet, you need to go to a slower powder such as H4350, and the .308 case improved will not hold enough of the larger volumes of slow powder. If you run the improved .308 case at high pressures, the primer pockets are too loose after about 3 firings. If you run light bullets in a 9.3, they don't have enough sectional density for anything large. And the more you "improve" the .308 case, the more you stuff-up its good feeding.
