"Americans who know nothing else about firearms are all too familiar with the name AR-15. It’s the semi-automatic weapon that murderers have used in many of the most notorious and highest-casualty gun killings of recent years: Aurora, Colorado. Newtown, Connecticut. Orlando, Florida. San Bernardino, California. Now, with modified versions, in Las Vegas, Nevada, and Sutherland Springs, Texas...A little bullet pays off so much in wound ballistics. That is what people who choose these weapons know."