Whether it be state law, federal law, a city ordinance. There’s not really much of a difference. The fact a municipality has banned firearms yet has one of the highest crime rates in the country should speak for itself. Look at New Orleans. The gun restriction in California have done nothing to prevent the murder rate from staying on par.
Hell those numbers from 2017 would be even hire if not for advancements in medical treatment and that’s a documented fact.
But the Chicago example is a poor one because you can drive an hour outside of Chicago and buy a duffle bag full of guns in Indiana.