Gun Control & RKBA

but a license would reduce the deaths. A few resourceful criminals or dedicated terrorists would continue.

OTOH, many spontaneous acts from the obvious emotional and mentally extremists (like Sandy Hook) would NOT have access to guns. It would be much more difficult if you had to show a license before purchasing a gun or ammo, or produce a license before entering a shooting range, or before going hunting.

If your required insurance to obtain a license depended on proper training and storage it would reduce the many accidental shooting and deaths of children.

You get the idea. We know (from other countries) that reduction in the mass number of guns will reduce deaths, but we also know that limiting easy access to weapons by dangerous people also reduces deaths.

I believe a license is the best and easiest way. If you have some other mechanism that works better, that's fine with me.