Is the dovetailed piece of steel that the mag tube is attached via a screw at the muzzle supposed to move freely? I can move mine back and forth with finger pressure, and I don't think it is supposed to be doing this. Also, I've had one hell of a time zeroing the rifle in at 100 yds due to shifting point of impact, which I believe is due to the mag tube being able to move. I've tried shooting the thing with a full mag tube and one at a time- no difference. When I tightened the screws down (the one under the receiver where the mag tube joins the receiver and the one in the mag tube at the end of the muzzle), accuracy went out the window, and the gun wouldn't even print 12 inch groups at 100 yards. Usually, it will shoot into 2 inches at that distance with iron sights, just the point of impact continues to shift. Should I send the thing to Marlin or get rid of it? I'm thinking that the mag tube is shifting, and when I tighten the screws, something gets put in a bind that exerts pressure on the thin barrel, causing groups to move drastically. Any ideas?