The liberal answer is:
If we restrict the quantity of guns in toto, those restrictions, in aggregate will keep guns out of the hands of criminals. Even if it saves one life....
What those restrictions do is CONCENTRATE guns into the hands of criminals.
Supply restrictions only work _BEFORE_ the reservoir(aggregate ownership) is filled but you’ll never convince a liberal of that. The reservoir has always been full and even if you put every commercial mfg of guns out of business and not make one more round of ammo, it will STILL be filled. Watch the documentary films on the guy who went to the gun markets in Pakistan. These people are fashioning guns and ammo by hand and it works.
To add to your argument: Even IF you could wave a magic wand and rid the entire world of Guns and the means to manufacture them ( An utterly impossible proposition except to the Leftists who nightly dream of Statist utopias)
You would STILL have edged weapons – weapons that favor those in society of greater physical stature, fighting skills and imbued with basic brutality.
Getting rid of edged weapons would involve ridding the world of ANYTHING that can hold an edge – Metal, plastic, stone, etc.
Most thinking persons will at least acknowledge that is an impossible proposition, but by this time the Leftists will have devolved into name calling and insults to distract away from the fact that they have lost the argument.