I shot several loads thru my 11-87 and 870, both 3 in guns.
My guns both liked the Hevi-13 2 oz 6 loads thru the Carlsons Hevi -13 tube which is a .662
My 11-87 has a 22 barrel and the 870 has a 26
The 26 in barrel put an average of 20 to 30 more pellets in the circle (10 @ 40) than the 22 in.
I shot Longbeard # 5, Nitro 4x5x6, and Hevi-13 7 also.
All shots were on a 65 degree day with no wind and I was using a Caldwell lead sled for a rest.
The Hevi-13 6 was a better pattern for me, but all guns are different.