High capacity magazines and semi automatic weapons with them should be reserved for the police or the military. In actuality, if you were going to state that weapons were allowed by the second amendment to protect the country with militias, then perhaps those weapons should be limited to the single shot flint loading types that were all that existed at the time of the writing of the second amendment itself.
If that were the case, then it would be impossible to have such mass killings. However, you are correct about one thing, and that is if we are going to have proper laws against such Assault Weapons and magazines , then they will only be as good as the enforcement of those very laws!
I would like to think that you and the other ultra conservatives here are not so stupid as to not realize that!!