In actual fact every armed society you might care to name, while perhaps being polite, was also generally violent. It was polite because being impolite meant violence might break out at any moment.
I reference the American West, early-modern Europe (Cyrano de Bergerac and the Three Musketeers) and samurai Japan. All three had elaborate codes of honor and politeness and were likely to break out in killing at any time.
In an odd way, some of this also applies to modern ghetto society, where thugs take violent exception to anyone “dissing” them. This has surprising parallels to some of the early scenes in Romeo and Juliet. With the obvious exception of much less elevated language.
I don’t know about the others, but with the American West, we also had “lawlessness”. That is, vast spaces with no police force and little regard to the law. (Same as today’s ghettos???) I think that had/has a lot more to do with it than just the presence of weapons.
In more civilized parts of the country where there is the presence of police and a regard to the law and a healthy number of firearms among the populace I’m pretty sure the numbers support a lower crime rate.
Out here in very rural northwest Illinois, all of my neighbors are armed to the teeth and no one can remember a shooting incident harming anyone other than coyotes and deer. Those animals are not armed. One group are predators and the other (the deer) are tasty.
Whether here or in Chicago, when seconds count, the police will be there in minutes to document but not prevent the carnage. As it was 150 years ago, we trust in government for protection in vain.
BTW, the reputation for violence of the American Old West is greatly exaggerated by Hollywood. Whatever violence afflicted early modern Europe, the disarming of the European public and the emasculation of its men gave us Hitler, Stalin, Mussolini, et al. The death toll rose dramatically and not just among the equivalent of our gangbangers. Artists, musicians, teachers, small business people, children, old folks and just plain innocent people were victimized.
In our country, before it is too late, we could use a man (or many of them) like Stonewall Jackson (or Enrique Gorostieta) again. It would also be nice if a code of honor like Japanese Bushido might spread among our upper middle class.
Finally, while William Quantrill, Bill Anderson, Jesse, Frank and Cole roamed the lower Midwest, they targeted those worth targeting on behalf of an otherwise helpless public. You may not care for their politics but their neighbors in the Ozarks did. If you want to bring up the massacre of the abolitionist men in Kansas, then simultaneously you should defend John Brown and his slaughter by machete of Southerners living in Kansas.
It was Illinois which produced Wild Bill Hickok and the Earp brothers among others. Some Earp family members attended my very traditional Catholic Church before shaking Illinois off their boots and moving to Idaho.
Also, without an armed populace, how DO we resist the Pinkertons?