I have a new Henry .22 lever action Rimfire rifle. I am not accustomed to counting how many rounds I have fired when I am shooting, but instead, I usually just fire away until I am out of ammo and hear the "click" of the hammer. Is this harmful to the rifle, or would it take a lifetime before there would be any appreciable wear? Do I need to change my ways? I've been away from firearms for the last 40-years, but it seems to me that I recall that dry firing is suppose to be a No-No. True? Flase?