Many countries which do not have a gun culture actually do have guns: for hunting, sport, cops, military. Switzerland has a gun pretty much in every household, yet they don’t have metal detectors at the entrance of schools and the only people I saw carrying an actual gun in over a year there were border guards.
I’d like to see a cite for this claim. Specifically, that there are fewer than 300 uses of guns in self defense per year in the US. I’m guessing there are several hundred such incidents in this thread alone.
I’m sure there are some. Probably inner city schools. None of the ones I have ever been in have metal detectors and I’m a detective who handles juvenile cases.