Kombi,
Think you'll find that loaded equally the 30/30 and 7.62x39 are pretty much ballistic twins. Most 7.62x39s are also now using .308 barrels not .311, so projectiles are pretty easy to come by and cheap ex-mil rounds for playing around with make cheap to shoot. In a single shot though I tend to agree the rimmed 30/30 would be nice. I'm also looking hard at the Rossi single-shots, thinking of picking a 308Win up for playing exclusively with cast loads in a rifle that won't brake the budget.
Cheers...
Con