"Open Carry" prevents gun crime. When one can see that a person carries a gun, he or she can take countermeasures.
"Concealed Carry" causes gun crime. When a gun is concealed, one cannot see it until it is too late to take countermeasures.
Would the country turn into Dodge City? No. Police and military carry guns openly and they do not shoot themselves.
An armed society is a polite society. Manners are good when one may have to back up his acts with his life.
-- Robert A. Heinlein, "Beyond This Horizon", 1942