Puzzled by why anyone would downvote a pure question. Wide distribution of guns is an obvious commonality between the US and Switzerland; if that's offensive observation please let me know why!
Someone may find the question offensive because of that.
According to this video you can't keep preciously-lent ammunition from the military. But you can for sure buy your own.
As to why people don't use it or aren't scared, I guess they just aren't as wild...