Even if we entirely ended the manufacture and sale of guns, there are far too many guns already in private possession for it to matter (I.e. there are more guns in circulation right now than there are people in this country). As a gun owner, it is obvious that to eliminate mass shootings we would have to eliminate private ownership of all semi-automatic firearms. That is so incredibly far outside the realm of possibility. The ability to engage in a mass shooting is not going to change; we need to engage the issue from other angles.