I think the PHILOSOPHICAL importance of an armed populace for a truly Liberal nation cannot be overstated. I personally would allow the purchase of rocket launchers, grenades, mines, and other such ordnance to people who pass background checks.
The simple fact is that per capita American civilians are by far the most heavily armed in the world, and that in the places where we have the most guns, there is almost no crime. I don’t know how widely known this is, but in a number of states you can buy and shoot fully automatic weapons. Kentucky has an annual machine gun shoot where people even bring miniguns.
Only when you get to Democrat bastions do the guns revert to the sole domain of cops and criminals, and only there do you see widespread gun violence.
None of this is complicated. The psychology is not complicated, and the epidemiological data is not complicated.