Those are some great patterns Devrep.
Thank you Rocketman, what I was trying to accomplish, was finding what the choke was by the pattern it produced.
If you had a 12-gauge gun and it put 70% of a shot charge in a 30" circle at 40 yards you would say it had a full choke.
I was trying to find the correct distance and pattern size to find the same thing about a .410.
The method you describe would tell much more about the shooting performance of a gun for sure.
Pete