RE: My Remington 870 jammed once more.
You may also have an issue with your extractor, check if it is chipped or damaged. It may be damaged just enough where it works sometimes and not others. I had a similar problem with a 7400 in .308 Win. As for feeding two shells and just turning them sideways sometimes, that is probably due to working the action too slowly. The 870 that I have likes to be pulled fast to cycle the next shell, if I go slowly, I will get the same results as you do.I also forgot to ask how much have you shot this gun? If you have fired alot of shots previous to this happening to your gun, I would bet that the extractor is the problem.
Axis