George,
Re shot string: The more open chokes have less shot in the center core and more on the outside edges that are not drafting. Thus they are more effected by air resistance and fall behind quickly making for a longer shotstring with the more open chokes. Most of the shot with a tight choke are drafting tight in a cluster.
Ash’s patterns prove the same. The open chokes GTH quicker because they are more affected by wind and fall behind.
However, some knowledge experts say pattern width is more important than stringing. Again that is basically what is shown in Ash’s circles.
