There are plenty of forums for gun owners, on the other hand gun control groups are probably fewer.
The problem is who is going to pay for a domain name for a non-profit cause, unless it's an organization with financial backing. But then they would quite probably register the .org.
The plural version of your name is registered so it's the most obvious end user. But again, are they willing to even pay anything. Most of the time forums are hobbyist level and barely monetized.