My 15 is only half built, but my AR-180b might as well be the same gun for this discussion.
I keep it in my gun cabinet with a fully loaded 20rd Pmag, (Hard to shut door with a 30) bolt locked back safety off.
I must not fear. Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain.