Actually, the higher-energy cartridges like .303 Brit and .30-06 are used even more rarely in crime than other rifle cartridges. Intermediate cartridges, which came into military favor following the second world war, allow the user to carry more ammunition per unit of weight, and to manage the recoil of the rifle more easily. It's also easier to manufacture an autoloading rifle to reliably fire a cartridge like 5.56 or 7.62x39 than one like .303 British.
Ferraris aren't very common as bank robbery getaway vehicles either. My point was that it should be possible to come up with some sort of regulatory regime that reasonably covers the entire range of uses - from personal safety to collection of exotica.
This isn't possible if one side's position is 'I get to have whatever I want, because'. You can't buy a thing that plugs into your wall socket that isn't UL certified, what exactly, is so uniquely special about firearms, of all things.
The great thing about mandatory liability insurance is that the government doesn't need to make any determination at all about how dangerous various kinds of weapons are. You think the threat of Gun Type X is overblown? Great. If that's true, market forces will ensure that the liability insurance for it is cheap.
