Suppose firearms makers had to get insurance on every weapon they put on the market & any time that weapon was used to facilitate a wrongful death, the company which engineered, manufactured, advertised & sold it was held financially responsible.
Well, they'd have to get insurance on every gun they made. Insurance companies would come up with the appropriate fiduciary metric, they'll insure pretty much anything. Then, through the magic of the free market, the actual price to society will be reflected in the price of the armament. Then the onus on stopping gun violence falls on the manufacturers, not on the government.
A gunmaker who deals with a shop in Virginia & keeps getting sued for deaths in New York will make an adjustment when it starts costing them money. I think you'd be surprised at how innovative they could be with suggestions for legislation when it hits them in the wallet. They might be just a little less innovative with the kill power of their product, too. If it hits them in the pocket.
Now I know that the firearms makers would say, "Hey, we just design, manufacture & market these machines. Sure, we do it with the purpose of making the easiest to operate & most lethal tool for killing people we can, but we don't know who's going to end up with it, or what they will do with it."
To which I'd reply, "Yeah. I know."