"How to tell an American from an Eurpoean: An American can tell a gunshot from a firework by sound alone."
As a pro-gun girl from liberal Massachusetts, I largely agree with you but have a few caveats:
These kinds of laws always bother me due to the nebulous nature of the definition of an "assault weapon" in this country. A quick search will tell you that there is no single definition for an assault weapon from a legal standpoint, but that it generally refers to "semi-automatic rifles, pistols, and shotguns that are able to accept detachable magazines and possess one or more other features." This definition includes almost every pistol ever created, as the defining attributes of a pistol that differentiate it from a revolver are that they're semi-automatic and almost always use a detachable magazine, except for some early designs like the Luger which use an internal magazine. Notably, the Colt AR-15 (the one all over the news for mass shootings) is not an assault weapon, and neither are rifles like the FN FAL, which was the French army's rifle for awhile during the Cold War. I have also seen stuff like AK-47 variants that are legally considered pistols here in the US, and even pump-action AR-15s, which would be completely legal under these kinds of bans despite being able to fire rounds almost as quickly as a standard AR-15.
It's even legal to anonymously buy the majority of parts for a gun online here, except for the lower receiver, which is a part that has a unique serial code on it that must be registered. Which brings me to my main issue with these kinds of laws: they always feel like stopgap measures which don't do anything about the actual issues but allow politicians to pat themselves on the back and claim they've solved the problem forever.
It's completely possible to have a country where you can own guns without having the issues we do, but everybody is too wrapped up in this 2nd Amendment spat. Countries like Australia have shown that it's possible. Australia used to have a gun culture identical to the US until they had a school shooting in the 70s. At that point, everybody in the country agreed to never let something like that happen again, tightened their gun laws and had a mass turn in of guns, and they haven't had a school shooting since. There's even a country in northern Europe (I wanna say Sweden?) where everybody has to do like 3 years in the army, and they can keep their service rifle after that time, and yet, they have no issues with mass shootings like we do here.
The belief that everybody in this country has a right to own a gun, whether they can be trusted to be a responsible gun owner or not, is probably the biggest problem we have towards actually solving this issue, and no one state can do something about it. These kinds of bans are always fairly easy to circumvent just by going to the closest state with relaxed gun laws, and they punish responsible gun owners who are going to freak out for suddenly being criminals for owning something that they bought legally. So we end up with these bans that treat a symptom and not the root causes while also pushing gun owners to vote for politicians who want to get rid of any regulation at all on guns.