I use corrugated cardboard as a backer for my "big paper" targets when patterning shot loads. No matter what size shot, or combination of shot size load, or choke tube, there are always shot that do not penetrate one layer of the cardboard at 40 yards. Normally the center core pattern penetrates completely and the outer core does not. At the end of any day, there will be hundreds of pellets trapped in the corrugations.
As the distance increases, the patterns spread out, regardless of choke or shot and the central core becomes much larger. Beyond 40 yards a turkey is much more likely to have some pellets that hit him but are not lethal...immediately. Many of us who have hunted for a few decades have shot at least one turkey that had evidence of being hit but not killed. I've seen gangrene in legs and thighs of turkeys that I've killed that were carrying shot for enough time to cause this condition.
I try to remember that turkey hunting is a sport and not something that I must do to survive. I set limits upon myself for how far I will take a shot and I've spent a lot of time learning to judge distance. I'd rather pass up a shot than take one, if I'm not sure that it's within the 40 yard limit that I've placed upon myself.
I don't spend any time attempting to figure out how to shoot at longer ranges. In fact, I spend most of my time, whenever possible, trying to lure a turkey closer to me before shooting.
I have 2 grandsons and I hope that the wild turkey is going to be available to them as a huntable species for their lifetimes. I want to pass along to them the ethics of hunting as much as the skills of hunting and shooting. I want them to remember what was important to me in all areas of my life and hunting is but one of them.
I don't and won't try to impose my personal standards on others but this is why I limit my shots to 40 yards or less.