As far as Europeans: The Swiss are all well armed and have gun training in high schools. They have a reason and they are as a reason one of the richest nations in the world and maintained that status for hundreds of years.
On gun laws: for some reason handguns require permits but rifles do not. In NY getting a handgun requires 9 months wait time, 5-7 character witnesses and an application to a judge. Rifles can be picked up as fast as they're shipped. A 9mm rifle is basically a handgun with a stock and a barrel but can be taken down to large pistol size.
On assault weapons: all weapons are assault weapons, I have knives and batons, those are assault weapons too. There is no reason to have a full-automatic, lacks precision and gets out of control unless you have a fixed mount.
Yes, America has lots of guns, but like Switzerland, it's a large area, there is no guarantee the cops can even drive to your house fast enough and as recently demonstrated, not an option if you live in a Democrat controlled area.