Ok, it's going to be perfectly clear after this question that I am a city boy now (grew up on the farm, but never went back).
What do you mean "public land where you can shoot?" I understand shooting parks and whatnot, but where can you go shoot that is not private land? How can you find non-public property?
I know that sounds like a ridiculous question, but I can't understand what you are talking about "public land." I can't imagine a place where you can shoot that is not private land. At least not without being arrested.
In Kentucky, a couple of the bigger areas:
1. The Daniel Boone National Forest
where shooting would be allowed just about anywhere (there are a couple of public ranges).
2. I think it is allowed in most areas of The Land Between the Lakes National Recreation Area
. I would call and double check on any restrictions there.
3. Check out a list of Kentucky state forests