I definitely agree on using the IC choke, at least with my Remington 870 Express. I had tried using the Modified Choke tube just to see how it would do accuracy-wise, and was not as accurate as using the IC tube.
I used this gun for deer season for a number of years, had a 4 power scope on it. Now I like using a .50 cal in-line muzzleloader. More of an HD gun now, minus the scope.
For best results with this gun, typically used the 1 oz Remington Slugger, 2-3/4" shell. Also the 1 oz Federal Tru-Ball loads.