Possibly of interest
“Experiments With (the length) Of A Choke Bore”
Forest & Stream, January 28, 1905 originally published by The Field (London)
https://books.google.com/books?id=6JbaHddByIUC&pg=PA84
A choke constriction of .016” and choke length of 3/4”, 1/2”, 1/4” and 1/8” produced essentially the same pattern percentage.