If a gun is of good and proper design then dry fireing will not hurt it. If dryfiring hurts your gun then you have a hunk of junk and would be best off selling it. The reason for saying that dry firing is bad goes years back when hard tempering meant brittle, and to cap locks. With a cap lock you will beat the hammer all to hell with dry firing and also the nipple. With early center fires the firing pin tended to be brittle. With a modern rifle help your self it is a good way to practice. A good rim fire the firing pin should not touch the barrel when in the fired position. On the cheeper guns this is not always the case and hence the tabboo of dry firing a rim fire. Again, if the rifle is of proper design then you are all right, if not sell it you do not need it and get a good gun.