As I noted in my comment and you apparently failed to understand, mass murders (primarily committed by mentally unbalanced white males) are statistically insignificant compared to the murders committed by and on young poor black urban males on a daily basis. The countries you're comparing the US to here, like Israel and Switzerland, do not have that self-destructive and violent subculture. That is why the US has more firearm homicides per capita than both countries with high rates of gun ownership (like Israel and Switzerland) and those with strict gun controls (like Japan and England).
Neither stricter gun control laws nor looser gun control laws will do much to move the needle on the US statistics because the bulk of murders are committed by and on individuals in a community that systematically ignores the law in the first place. Solving that problem will require a comprehensive social policy that will dismantle large aspects of contemporary African American culture. Unfortunately, it seems that any such suggestions would be political suicide, and therefore are avoided by all politicians.
Eliminating mass murders (which, while currently statistically insignificant, should still be targeted), OTOH, would best be accomplished by providing comprehensive and free asylum-based care to the basket cases that commit such atrocities. Parents should not be allowed to overrule the judgment of medical professionals in such situations.
Of course, none of this changes the fact that eliminating the sales of guns without background checks (such as at gun shows) needs to end right now, as it is a no-brainer.