For small game I have used the .32-20, .38/.357, .22 Hornet, .222 and reduced loads in 7.62x39 or .223.
I really like the .22 mag for smaller critters as well.
Another rifle I like is the 77/.357. I use both .357 and .38sp. rounds depending on what I'm after.
A 158gr. full wadcutter over 2.5gr. of Blue Dot works fine.