The level of gun violence in the US has nothing to do with gun control laws. Other nations with much laxer laws have less crime, and some with stricter laws have more.
Compare Sweden (private ownership of automatic weapons) to mexico (strict controls on gun ownership) and the real causes stand out like a sore thumb: mexico suffers from poverty and gang violence, Sweden does not.
The reason why the US has a crime rate more like mexico than Sweden has to do with demographics and economic factors. Unlike Sweden or a Canada, the US has almost no social safety net, a lot of poverty, and big problems with gang violence.
It is the income disparity, not the gun laws, that make the US so different.
Until about the seventies Canada had lax gun laws with private ownership of automatic firearms, etc, and we STILL had much less gun violence than the US.