OP - You didn't mention whether your .357 had adjustable or fixed sights. Fixed-sight guns are traditionally set up to hit POA with 158-grain bullets, though the 148-grain wadcutters tend to work fine.
If you're going to be shooting lead bullets, make sure the bullets fit the throats in the cylinder. The easy way to test for this is to drop a bullet from the rear of the cylinder. If it sticks in the throat but you can push it through with moderate pressure using a pencil or something similar, you're good to go. If it falls right through, it's too small and there's a good chance it'll tend to lead the barrel. If it's too big, it'll still work but won't be ideal. The default size for .38/.357 lead bullets is .358.