Gun control would inevitably prevent some violence, but it does nothing to address that actual causes of the violence.

Gun control in conjunction with social democratic reforms aimed at targeting the roots of violence would probably be a good thing from a utilitarian standpoint, but without socialist revolution there would be no way to guarantee the security of social democratic reforms.

That being said, I don't think that meaningful social democratic reforms are really possible given the current realities of neoliberal contradiction and the collapse of western imperialism.