Before there were Turkey Targets

Instead of a fancy store-bought turkey target, I still like to do it the way I was taught before folks had such things: Take a Dixie cup and put it upside down on a stick about 18" high. Use a backing board with newspaper. Back up to the chosen distance and let fly at the bottom rim of the cup. The rule of thumb is that two pellets in the dixie cup will kill a gobbler at that distance. I've never known that rule to be proved wrong.

Keep placing newspaper on the backing board to see the whole pattern. Eventually you'll chew a hole through the bottom sheets of paper and it will show you if your aim point is off one way or the other.

One thing you'll get a handle on is exactly what it takes to kill a turkey. Sometimes the cup gets blown off, sometimes the stick breaks, sometimes not. If you figure the stick is his neck bone and the cup is his noggin, you can get a feel for it. Rather than just counting pellets, when the cup stops flying you know you're probably exceeding the effective range of the system.

For all my trying to squeeze 45 or 50 yards out of shotgun for 25 years, I still take the vast majority of shots at 10 yards or less. I daresay more turkeys are lost from patterns that are too tight, missing at 10 than too open at 40. Aim for the base of the neck instead of the head. The base moves less and more of the pattern will get where it needs to go.