That the best ya got? Why stop at 20 and promote some survivalist web site?
Comprehensive list courtesy of the NRA.
http://www.gunowners.org/fs0302.htm
The reasons for these lists I believe are so gun folks have an idea of businesses to avoid ( NO GUNS NO MONEY) hit them in the pocket book.
Since you see fit to critique my list let me do yours. While your list was long, most of it is worthless. Take out the sports teams, cartoonist, poets, actors, stuff no ones ever heard of, no brainers like New York Times and colleges and you're left with very little to sink your teeth into. Anytime you list Hollywood celebs, it's more effective to list the handful that are pro gun.
Hallmark cards and Levi Strauss, now those are business I can avoid when I purchase items, I do business with their competition.
Don't get me wrong I do appreciate your list as I have read through it several times but I don't know what to do with things like The Council of the Great City Schools or Disarm Educational Fund. If you're going to list St. Louis University might as well list UNL and UNO.
Oh by the way your list is from 2009.