I actually listen to a bunch of them.
http://gunrightsradio.com/ Has a bunch of good one. I listen to the Gun Dude, Gun Fighter Cast, and Pro Arms Pod Cast. I have only really started getting into gun in the past two years. I rarely meet anyone who listen to any gun podcasts. I would definitely suggest listing to an episode of the Gun Dudes, its really not to different than listen to The Mens Room on the radio. Besides the fact its just some random dude like most of us here, Talking about guns. Definitely worth checking out.