If these Hevi-13 7's just don't have the umph to get the job done at 40 yards like some say then I'm just going to have to see a bird walk off from this at 40 yards before I believe it.
Mossberg 835
20 inch barrel
Hevishot Choke
Hevi-13 3 1/2 inch number 7
40 yards
285 in 10 inches

Just for fun I tacked up a Primos turkey head target and gave it a blast at 40. Centered it pretty well. 34 pellets in head or neck "BONE". If you count every pellet that drew blood it was in the 80's.
Can't wait to conduct a field test on a gobblers head.