Well, it was overturned 10 years ago by SCOTUS. But, congress passed a new version of it a few years later and this version hasn't yet been overturned. The original law was overturned for lack of IC Nexus. So, the 2nd time Congress added an entire paragraph of Bullshit about how guns hurt education and bad education hurts IC, etc...
But, there is a clause that says you can have a gun in your car within a school zone. Another says you can keep a gun in your car on school grounds if it is locked and unloaded. I believe there is a clause that if you come within 1000' while hunting or something like that and another that excepts possession in your home and on private property. The real problem is that if you step on the side walk in front of your house, you have commited a federal offense CCW be damned. But, if you get in your car you can take it wherevr you are going. But, you cannot have the gun off your property if you are within 1000' of a school unless you are within your vehicle.