I don't want to sound like a jerk, but when you have $5K worth of guns, a $500 investment in a proper gun safe is not that much money:
http://www.cabelas.com/cabelas/en/te...=cat20799&rid=
At 200+ pounds, being the size it is, and bolted into the wall studs in your closet, any thief is going to have to make a hell of a racket to bust it open and/or move it.
This is a good lesson for all you new players, too: you're expected to treat your airsoft guns like real firearms at the field, so why not treat them like real firearms at home, too? Buy a gun safe, and use trigger locks.