I live in Switzerland and I have been through military service and yes: I had my assault rifle with 24 rounds of ammunition at home. So here's my theroy of why the swiss are not using the guns to kill each other senselessly.

First: Every male with a gun has gone trough boot-camp. He has learned to live with a weapon, shoot with a weapon, walk with a weapon, handle a weapon, clean a weapon, hate a weapon (on the walks), love a weapon. He has made himself aquainted with his weapon - even learnt the serial-number by heart. He knows what his weapon is capable of - and respects it. It's like martial arts in a way. When you practice Karate you soon learn how to inflict injury or death on others. You learn that you wield power. And you also learn instinctively that the power is within you all the time - you don't need to prove it by showing off. There is respect for your powers and you become calm and confident.

Second: Swiss people are not constantly barraged with mindless violence as US people are. Here, no parent would take their 4 year old child into a movie that was rated for a much older audience. (As I have witnessed in a US movie theater: Kids that cry because they are frightend of what they have to see on the big screen.) The quality of the television programming here is slowly detoriating to lower standards but still - we are not there yet, so there is some hope left.

Third: Any male who has gone through the military would not use his assault rifle because he then would have to explain the missing rounds at the next inspection of the stuff you got from the military to the inspecting officer. And that would be really difficult and embarrassing.