I'll try to answer as accurately as I can. The narrative that I read into the media that I consume is that (1) the US has ineffective gun control laws, and (2) that there is widespread availability of a variety of guns and ammunition to anyone who wants it. I believe that gun ownership is a constitutional right in the US. I was aware that only some states are "open carry." I am not surprised to be corrected that some states have strict legislation, but I was not aware of that, and it does not seem consistent with my understanding of gun freedom in the USA.
I triangulate (1) from the ongoing mass shootings in the US and the few mass shootings that I recall from my youth: for a long time it seemed to me that the 1996 National Firearms Agreement [1] had been effective here in Australia.
[1] https://en.wikipedia.org/wiki/National_Firearms_Agreement