Nothing against the OP, but I have to agree with TG-3006. Again, I don't have a lot of use for a 30-30, but its darn near a friggin magnum compared to a .357!
The price of an extra box of bullets is a really poor excuse to use a .357, especially with all the other costs associated with hunting.
Besides, a regular box of 30-30s would be cheaper than .357 ammo!