Australia had a mass shooting in 1996 and pretty strict gun control came in. Now it’s only really sport shooters (who are a pretty responsible bunch from my experience), rural property owners with a good reason (pest control largely), certain occupations like specific security (cash transport for instance), cops and military that have guns. And criminals.
We still get the odd shooting but they’re pretty rare and to my understanding, almost never done by legal owners.
I’m not sure what things were like back in 1996 but I don’t believe we really have the gun culture so there’s not much opposition to gun control by the majority.
I’ve only quit jobs when moving, one I gave 2 months notice and confirmed I would be around for two peak periods. I have done what you did without the vacation bit. Tell them first and then give them the letter.