i live in southwest washington state, the unit i am in specificly says "no rimfire or centerfire rifle may be used" pistols yes, but revolver style only,
WOW, that is harsh. Not even rimfires? And only revolvers? What difference does it make if it's a revolver or a pistol? I trust you know what you're talking about, but it makes no sense to me.
Back to shotguns, 12- or 20-gauge with buckshot, full choke, and best of luck to you.