rear O ring for bolt?

I picke dup my Tippmann today, and when I got home, I looked at the rear side of the bolt, and there was a light grey O-ring on a diagonal not connected to anything.

I figured If I cock it, it would go back into place. It's now at the very rear of the gun.

There's a picture of it, the o ring is circled. The ring is now pushed back to were that cap is on the rear end of the gun..

Is this normal? And if not, is it back were it's suppost to be? Should I take it appart and put it back?

Awesoem thanks you guys.

I looked in the ownwers manual, and I figued it was suppost to stay back there, not slide down. But I cocked it, and released the trigger while holding the bolt (Not to damage it) And it's back by the end cap, like you guys said.

Thank you, once again.