Remington 870 Super-mag barrel
 

The Remington Super-mag has a 3 1/2 inch chamber that is almost without a forcing cone. I sent mine to have the forcing cone polished out. Now the transition is very smooth in the barrel, I hope it helps the pattern. I haven't shot it yet. I also had a bead installed on the middle of the rib. W hat has been you experiences with polishing out the forcing cone?