I killed deer this past year with both. The .308 runs the same bullets 500 fps faster, and to me is more of a good, general purpose big game round for light rifles.
I'm sorta on a kick for smaller cartridges for deer, that still do an adequate job. The .30-30 fits that mold nicely, as it has for a long time. A single shot lets you use any bullet you want.
Now all that said, why isn't there a +P .30-30 load? The Contender is also chambered by TC in the .375 Winchester, which is the same head size as the .30-30, and much higher pressure. There's now Ruger #1's in the caliber, and other strong rifles, so it seems to me one could judiciously run the .30-30 a little hotter.
