I'll repost what I wrote in response to Lulu's original comment:

The problem is too many damn guns, of whatever kind. If you want to disincentivize gun ownership, what's your most effective tool? Cost.

It has clearly been shown to work in stopping kids from smoking. They may still imagine smoking might be cool, but they can't afford the habit's maintenance costs (10 bucks or more a pack). Meanwhile, plenty of other "cool" things are cheaper.

The price of a pack is mostly tax, but the principle is the same as mandatory gun insurance: you are choosing to impose additional costs on society (in this case medical), so you should pay for your decision up front.

Your moral-hazard argument misses the point, DF. No one is going to use their gun more recklessly because they are now insured for liability.

The idea is less to compensate victims than to reduce the appeal of guns generally by spreading the cost to society among all gun owners -- the good ones along with the bad, because everyone thinks they are one of the good ones until something snaps.

It's what we do with car ownership, it's what the U.S. now does with health insurance. There's a cost that follows from having so many guns floating around, so it's only fair that those who endorse that situation absorb it. You have three guns, you pay three times as much. Twenty, 20 times. You're still free to own guns, but owning them is no longer free.