I submit that it will be far easier for the Atheist community to make thoughtful and topical contributions for a week without a single reference to their Atheism than it will be for the HyperChristians to go a week without an appeal to god, a scripture quotation, or a claim of (dubious) higher moral foundation. That, to me, means the Atheists and other non-believers have the superior claim to polite discussion of the issues of the day here than the Holier-Than-Thou sects. If they want to go off and make their GodGunsGuts.org web forum for their purposes, then so be it.
I do not, however, see how a gun forum has any hope of divorcing itself from political discussion. I can't imagine a single topic which could be started here that would not be touched by at least one law in at least one jurisdiction of a member. "Can I modify this model X handgun to add an ambidextrous safety?" "Well, over here in jurisdiction Y, there's law Z which makes it illegal to do any after market modifications to any firearm whatsoever." *sigh*
I like the idea of going a week and seeing who can lay off religion more, the faithful or the faithless and decide on rule changes based on that result.
For the record, I have no intention of ever discussing my sexuality on this forum, precisely because sexuality is not a topic of choice. If the other members never discussed their religion, I'd never have the remotest impulse to discuss mine. Proselytization is as proselytization does.