I am working on a Model 97 takedown that the Bayonet adapter and heat shield had been removed and a standard barrel hanger bracket,magazine plug and takedown pin had been installed.  I am going to remove these parts and reinstall the correct magazine plug but once these parts are removed what keeps the magazine tube from turning back and forth once the takedown pin has been removed…. all photos i have seen of Takedown trench guns have the takedown pin removed and i am thinking that it would not be a good thing for the magazine tube to be able to twist into the takedown position on it’s own?  I realize that the magazine tube will be somewhat trapped into position by the bayonet adapter and can’t actually go into takedown position but it seems that there should be something to hold the magazine tube from turning?