I shoot a Rem. 870 Express and I use the Rhino/ Nitro 3x5x7 3 inch shells, that is the best set up I have found yet.
Expensive yes BUT I have never missed with them and I only shoot one shell a year Hence the one shot one kill.
I heard a guy shoot 4 times a few weeks ago I say pattern your gun, slow down take your time and if you cant do that their is always another turkey.