So now that you've had some time to work on my first couple of suggestions, it's time for another idea. This one is sort of courtesy of Michael Bane and his Down Range Radio podcast, although it's something I've been practicing on a personal level for a couple of years. I just hadn't considered telling other folks that they should do it. (Silly me.)
As a firearms owner, GET OUT OF THE CLOSET! Stop hiding, stop disseminating and be proud of who you are. You are the current frontman (or frontwoman) of all those previous generations of gun owners, ranging from the first European immigrants to this land up throough today. Be proud of your history!
If someone asks you what you did this weekend, tell them directly, with no sugarcoating. "I went to a gun show." "I went to the range and shot pistols." "I competed in a rifle match."
If someone asks you about your hobbies, tell them. "I collect historic Lugar pistols." "I do custom reloading." "I'm a home gunsmith."
Put your gun books out on the bookshelves the visitors to your home can see--stop letting them sit in the basement with the reloading presses.
Get the idea?
You will get some odd looks from some folks, and some of those folks will look at you funny for a long time. However, from personal experience, I can tell you that your hobby will soon become an accepted part of you. (By and large at any rate; there are always going to be some who think you are an e-e-e-vil monster, just waiting to "go postal" at the least slight--screw them, their psychological issues are theirs, not yours. Let them deal with them on their own time.)
If it works for you as it has for me, you'll start getting more people who open up to you about their firearms ownership. You compare notes, trade suggestions, maybe pick up a member for the NRA or your range.
Everybody wins from this tactic--except the anti-freedom forces.