I rarely mention gun rights, politics, etc on facebook. Like it or not the NRA is seen as a political organization who oppose President Obama and his cohorts by many. Several of my co-workers and customers are Obama supporters, so being too vociferous about the second amendment might
As far as I know though, most all of, if not all of my 150+ facebook friends are pro-second amendment and I actually know all of them quite well IRL, so I feel confident saying that. I try often to change the perception that the NRA is a partisan political organization, but I have to do it tactfully.