Swab out the bore with a cleaning patch saturated with Birchwood-Casey SHEATH, then rub all the steel surfaces with that patch. Then you can just put the rifle in an empty corner of a closet. You could also place it in one of those silicon-impregnated Gunny Socks they sell at Walmart for added protection against rust and light impacts of foreign objects.

(I note in that corrosion protection test they did not test SHEATH. That eezox may be better, I haven't used it. But the SHEATH protected my blued guns very well in coastal Alaska, which as everyone knows is the very WORST environment for guns on earth!)

NEVER STORE a gun in a soft gun case! They attract moisture and cause rusting!