I'm assuming drug rings and other miscreants who are really motivated will always find a way to acquire guns like they do in every country with gun laws.
Less guns, less shootings, less gunshot deaths, it is that simple.
But how to get to less guns in a country like the US, that’s the real puzzle.
This would be a lot more convincing if you included details like a country that isn't in the Americas (this is notable because guns flow from the US to Latin America in a reverse flow from the drugs that flow) that has strong gun laws and lots of gun violence.