I have just come back from trying to pattern my shotgun again and with the same results. I have tried Fed 3.5" #5, Win 3.5" #6, Win 3.5" #4, Fed 3" #6, and none of these pattern worth a hoot in my gun. I am shooting an 870 with a ventilator choke from 40 yards. I get an average of 4-10 in the entire head (not vitals). The highest # in the head was 14. I then moved up to 30 yards and the pattern was better, but not what I was expecting. My wife says I am spending to much money on shells and I am actually beginning to agree. Do you think it is my gun? If I lengthen the forcing cone do you think it will tighten up my patterns? Any help is greatly appreciated. Thanks.