I know nothing about setting up website, but heck, I don't anything about guns either and that doesn't keep me quiet.
To increase traffic to the handguns site and the other ones I propose tabs across the top of the website-
just like the ones on the Continental site (I randomly picked that one for no apparent reason) that say "business travel center" "vacations and specials" etc. except they would say "equipment exchange" "Industry Forums" "handguns" "ak-47" and so on.
If there was a visible "handguns" button exposed all the time I think people would be more likely to click it. I admit the "site navigator" SEEMS obvious but it just isn't working out that great.