away, oil-spray the .22 pistol,hide it, blend in with the sheep. The can will take care of a LOT of the risk of any testing showing that you've fired a gun recently, count upon that. If you incorporate a slidelock, to keep the .22 auto from cycling the slide in the normal fashion, it will be "quieter", and even less risk of having a "nitrate" test show you as having fired a gun.