I have a S&W 6906. I bought the gun from a local dealer who said that he knew the guns history, and that the previous owner probably never shot it. The gun looked like new and had no signs of wear. Only after shooting and cleaning the gun for the first time did I notice that if I pressed down on the barrel hood, with the slide fully forward, the barrel could be pushed down. My other third generation S&W pistol barrel is tight at the hood in full lockup and can't be moved at all. When pressing down I would guess that the movement is at least 1/16" but can't tell exactly. Also, I found that when the barrel moves downward the slide moves rearward slightly. If the slide is held tight, the barrel can't be pushed down. I I shot at least 150 rounds through the gun, without any problems. I only have one other S&W third generation to compare it to, and that one is tight and won't move. How much barrel movement, if any, is normal at lockup? Should this be a concern?