Face it, folks. There is no solution. It is a plain and simple fact.
If the government bans firearms or any sub-set of firearms, the only people who will comply with the ban are the law abiding people who are not the problem. The bad guys will not comply. All you have done is to punish the law abiding people for something they did not do and you have done nothing to hinder the bad guys.
The only way of discovering the limits of the possible is to venture a little way past them into the impossible - Arthur C. Clarke