Ok, putting aside the fact that gun crime is significantly less in countries that have had gun control enacted within living memory
I don't have a solution for you, but thinking that gun control is the solution because "it must have worked elsewhere" is part of the problem. I live in the 2nd most gun friendly country in the world (a few days ago I received an invitation for a "rifle shooting course while flying on a helicopter"), but despite that we're constantly in top 10 safest countries of the world.
I guess one difference is we don't have too many real firearms among criminals. Also, we somehow lack the dumb people placing loaded guns within the reach of toddlers and things like that. Furthermore, no killings at schools, regardless of weapon of choice. Somehow our kids don't feel the need to murder their schoolmates.
We also have almost no knife crime (hello UK!) despite having no laws banning the carry of cold weapons.
I'd personally say the problem is in the people and the society. The use of weapons is just a manifestation of such problems.
These are all great points. Here in the USA we lack a strong social safety net, we lack healthcare as a right, and we have a long, historic racism due to hundreds of years of slavery and abuse of indigenous peoples. We have a militarized police force that is completely untrusted by significant populations. We have social problems that don't exist in some countries and its hard for me to believe (well, as a liberal it is) that some of those differences are not as or more reasons why we have more crime issues.
That said given that fact that suicide is the #1 gun related cause of death in the USA and countries like Japan that have crazy hard core gun control have more suicide by population count tells me there's a lot of complexity and nuance here. It's hard to compare since crime gathering statistics vary a lot country to country. Yes other countries that ban guns have less gun crime; but they are not Star Trek style utopians with no crime at all. Wasn't there just a mass killing style attack in the EU where the person was using a bow?
One thing for sure, banning ARs will have a statistically insignificant impact on gun crime. When the US banned ARs for 10 years they did three studies and that was the finding (and the commission was run by a Democrat that really really wanted to find proof that the AR ban was a great idea). Both Australia and Canada did similar studies after banning ARs and both countries had the same conclusion. Those studies are out there in the public domain for anyone to read.