I have an SB2 Frame and both barrels I have for it exhibit side to side play when locked up. And yes I can take some of it out with the forend on. And I do understand how to fit a barrel. But I find it interesting that both barrels would exhibt this problem. The one I have really played with the most will allow .004 only one side It will not close with with anything on the other side. Is there a problem with the Hinge pin or is there something else i am missing.