Ooh, I think I have the same model. It's gonna be a bitch. I don't see how the end can unscrew the end (where the barrel lug screws in), and trying to remove the entire tube from the receiver seems almost impossible. Fuckin thing sucks.
I thought you meant it (the spring or follower) was stuck inside not that the nut on the et.nd of the tube was stuck and one of the things you were trying to do was take off the nut to take a look at it.. I think your title was confusing...