You have to dig a little deeper. Swiss gun ownership is primarily guns owned by those in mandatory military service. The have guns, but most do not have ammunition with the guns. The majority of Swiss gun owners simply cannot shoot someone with their guns without first obtaining difficult to obtain ammunition.

Looking at the numbers alone is not enough. Just like looking at the US numbers alone doesn't really tell the real story. Guns are definitely part of the problem, but it's the rest of the culture and economic factors that tells the story of why the US numbers are so high.