Glocktalk.com would be a good place to start a thread as well, if it hasn't been started already. As well, the AR-15 web site.
Union doesn't have to be a bad word. Remember, "We the people of the United States, in order to form a more perfect UNION..."
I got to add, I know plenty of Union members that are both conservative (if not libertarian) and strong supporters of the second amendment. The Gun show Protection Union needs a web site.