There’s no country with 0 crime, but there’s incredibly safe countries with gun control, and they don’t have many issues apart from special cases.
The connection guns=violence is not really a thing. I used to be very anti gun before I did my research. There's a lot of bias among Europeans and not nearly enough education on the topic
I mean you’re a fool if you think it won’t greatly reduce it. It’s not without reason that the US has particularly high crime rates in comparison to other first world places.