When fielding questions regarding deer rifles, I frequently got the one: ". . . my BIL says I should by an SKS, 'cause it shoots gooder than my 30-30 and the ammo is cheaper."
Case capacity wins every time in any discussion of the theoretical limits of two cartridges. Isn't there about a 25% advantage in favor of a 30-30? I'd say that pretty well says it all.
Yes, a souped-up 7.62 X39 fired from a nice bolt gun will do about the same job on a deer as a factory 30-30 up to a point, but having spent a good part of my life around KY hillbillies that spent the better part of their lives trying to make their 30-30's work like aught-sixes, I'd give the edge to the 30 WCF.
Yep, and if you want to soup up the 30-30 with Paco kellys 40,000 cup handloads {same pressure the 444 Marlin is loaded to in the 336 action} it really stomps the 7.62x39.
