You don't have to go all the way to Europe. Canada exists. Canada is culturally very similar to the USA, has a similar incidence of mental health, has similar usage of drugs to treat mental health.

However, Canada has stricter gun laws. While bolt-action hunting rifles are legal and unregistered in Canada, owning one involves getting PAL, which is similar to earning a driver's license. It involves lessons and tests.

And more... murder-y weapons like pistols and "assault-style"[1] rifles are either banned or restricted. Restricted means the gun is registered, you take extra certifications, and you fill out paperwork just to transport it from your home to the firing range, which is basically the only place you can legally fire the thing.

Shootings still happen. There was a tragedy in Quebec City a few years back where a "great replacement" nut shot up a mosque (which illustrates how we have the same cultural problems as Americans). But the number, per capita, is tiny compared to Americans.

It's hard to escape the obvious conclusion that the reason there are so many gun deaths in America is because guns are so poorly controlled.

Most of the street crime guns here are smuggled over the border (America is to guns as Escobar's Colombia was to cocaine), so the lax gun laws don't just impact the USA.

[1] yes I know it's a vague term but you also know what I mean don't @ me.