In response to Michael Corey's remarks in his letter: Stop filling your students' minds with such rubbish and they won't take such nonsense away from your class. Tell them the truth instead of the "progressive" talking points; that 99.9999% of 100 million plus gun owners and 300 million plus guns are never involved in killing or harming anyone.  That infringing on the constitutionally protected right to keep and bear arms by banning whole classes of arms and accessories is an emotional response to a tragedy, not a reasoned one, and that emotions are poor foundations upon which to build laws. 
Example: In 1986 the federal government banned the sale of arms that fired more than one round for each pull of the trigger manufactured after the law went into effect. As a result of the law, people figured out ways to substantially increase the rate of fire for their autolaoading arms. Example 2: The ban on certain autolaoading arms ensured high sales of those arms when the ban expired.