It's really hard to beat the 30-30. I shoot both, as well as a 38-55, and my scores with the 30-30 are usually better. It shoots flat, recoil is mild, and uses less lead and powder (once you reload for it) than the other two. After 40 rounds behind the 45-70 I've had enough and start to flinch. And don't get a 38-55 until you are an experienced reloader, they do have their quirks you probably don't want to deal with yet.
As for pistol ctg., if your 45 shoots well keep it. There's nothing a 357 will do that a 45 won't. My 357 is so much pickier to make work than the 45 it's not funny. I like both, and the 357 is cheaper to shoot, but the 45 will outshoot it any day.