In the conclusion to his powerful analysis, The Costs and Consequences of Gun Control, David Kopel of the Cato Institute writes:
Firearms in the hands of law-abiding citizens enhance public safety. Firearms in the wrong hands endanger everyone. Responsible firearms policies focus on thwarting dangerous people and do not attempt to infringe the constitutional rights of good persons. Background checks on firearms sales can be improved by including more records on persons who have been adjudicated to be so severely mentally ill that they are a genuine threat. Extending federal gun control to private intrastate sales between individuals—and to firearms loans among friends and family—is constitutionally dubious, and imposes severe burdens for no practical benefit. Such a system is futile without registration of all firearms. Gun owners have justifiably resisted gun registration because it has facilitated gun confiscation in the United States and other nations.
It is false to claim that common firearms are “assault weapons” and it is false to claim that common magazines are high capacity. Outlawing standard firearms and their magazines deprives innocent victims of the arms that may be best-suited for their personal defense. Sensational crimes are often used to push poorly conceived laws which criminalize peaceable gun owners. The most effective paths to preventing mass shootings are improving access to mental care and removing impediments to lawful self-defense and defense of others.