One thing that I feel must be mentioned to put that list into perspective: "guns" can mean a range of different things.

For Sweden (9:th in the list, with around 1/3rd the number of guns per capita as the US, and also where I live), I'm pretty sure a very high percentage of those guns are rifles, used for hunting.

Handguns, which seem very common in the US, are very rare among people who would have their weapons registered. I guess almost all such owners are sport shooters; owning a handgun for personal self defense just doesn't exist as a use-case.