So far I love it, but one thing worries me. When I tilt the gun forward, I hear what sounds like an internal part moving inside the gun. Whatever it is it only sounds like it moves a millimeter or two. Is this a normal thing to happen? Also, I have a habit of repeatedly dry firing the rifle and cocking the charging handle (gun is clear every time). I've only done this 10 or 20 times ,is this in any way damaging to the gun?