Desperado85

I have recently purchased an M2 in March and I love it. However on monday I noticed something and im not sure if it is good or bad. Whenever i pick the gun up and move it around at different angles, I can hear the inertia spring inside the bolt move back and forth. The only time I dont hear this is when the action is closed and the bolt is locked forward. Is this normal? I have cleaned it and taken it apart over a dozen times already and have never noticed this. Please let me know if anyone else experiences this. Thanks in advance for the help!