Hmm that is remarkable - the table says the USA has 120.5 firearms per 100 citizens, the highest, of any country, and #2 on the list is Serbia with 37.82! So, the USA has more than 3 times as many firearms per citizen as any other country on earth, if that table is to be believed. (I don't know how incomplete the list is.)

And that global map is..interesting too - with the exception of Canada and Cuba, the Americas are really homicide central, and to a surprising degree.