The business of selling AR-15 rifles is getting tough. By my completely unscientific estimate, there are 976.23 trillion companies making different types of Modern Sporting Rifles. That tsunami of supply, combined with the fact that Hillary didn’t win, has them overflowing the warehouse doors and spilling onto sidewalk sales across the country.

As an economics major in college with a GPA assuredly more than 1.3, I can attest that a big and readily available supply of...