I ran an 870 for a decade, first gun I bought myself in '95, sold it in '05. That gun took a beating but I did have issues with 3" magnum loads and 3" slugs. They occasionally jammed, usually after the gun warmed up a little. I had to dismantle it twice in the field to get the shell out. It had the problem with multiple ammo companies so it was a material issue. Took it to a gunsmith and he said everything appeared to function appropriately and that it might be swelling. I had enough of it with that gun because it cost me a few birds and two nice bucks on occasion due to jams. I upgraded to a SX2 when I caught a sweet deal. My duck gun is going to be a Berretta A300, it cycles really nice and it runs like $650 for a synthetic.