huntingsgr8,
If you especially like 7.62x39, and .223, you can duplicate them with rimmed cases. The .303 Savage case will make rimmed 7.62x39, and 5.6x50R cases will make .223rimmed cases. In my opinion, however, Oskar has the best solution. The 35-30/30 he mentioned, can duplicate 9.3x72R ballistics, in a shorter case.
Mike