Just as vehicle owners and drivers are required to maintain liability insurance or show proof of financial responsibility, owners and users of firearms should be held to equivalent accountability for their weapons, and be required to purchase liability insurance for them. The insurance industry will determine rates as it does for all other risks it underwrites, based on risk factors such as personal history and background, prior incidents, certifications and training which reduce the risk, etc.
This is a common-sense, economics-based approach to reducing accidents and other irresponsible behavior related to private ownership of firearms. Its effect would be greatly strengthened by requiring proof of insurance for every transaction involving ammunition, as well.