To answer the op, part of the thing is that in Australia very few people have guns, so hence no one really worries about them, it s a pretty big deal to hear of a gun related death here. This somewhat proves the whole if the civilian population doesn t have guns, less criminals use them as they are much harder to get hold of, and much more traceable, also they don’t feel the need to. This also happened in the UK where police no longer carry any guns, hence criminals don t feel the need to carry them either. However in the states there is a very strong attitude that you need protection from anyone, partially because they are so easy to obtain, considering many states you can walk into a gun store and get one off the shelf pretty easily, when I lived in Georgia I was pretty shocked at how easily I could have gotten a weapon. However the trouble is, is that most people don t know how to handle a gun properly, also they don t think about the consequences of shooting a gun. Hence you hear of wives and husbands shooting each other when they come home late, also you get many cases where someone shoots down a road at a thief and ends up killing an innocent bystander. Plus many break ins where the owner of a house own a gun result in a thief overpowering the owner and shooting them, or sneaking in and being able to grab a gun right out of a draw or such in Australia there is a law whereby you have to have guns looked away in a secure gun safe . Also people don’t realise that if a thief breaks in to your house and you shoot him you will get charged for assault as more likely than not it will be considered unnecessary force, some places you might get away with it, but plenty of people are in jail because of this. basically there are a lot of stupid deaths because of the prevalence of guns in America, aka, black boy being shot for carrying skittles and ice tea though racism was probably the motivation, if the guy wasn t able to buy a gun so easily it never would have happened . However there is such a culture that guns are necessary, also the NRA hold enough power that the general attitude is unlikely to ever change, so people continue to feel more threatened and so they insist that they need a gun. tl;dr you can have some semi autos in Australia, strong gun culture in America leads to many stupid deaths of innocent bystanders, also strong fear culture means it wont go away, plus Aus and UK show that less guns less gun crimes.