After reading Michael McIntosh's writings on choke and how he could break targets beyond 40 yards with a cylinder bore I hung a clay target on a bush and measured off 40 yards. I used a cylinder bore gun and shot at it with 1 ounce of 7 1/2 shot and it didn't even move. I walked up to it and could see where a pellet had grazed it but it didn't move that I could see.
I repeated the shot about six or seven times with the same result.
(Once it did fall off the bush without breaking)
This led me to beleive that MM either could not judge distance or he was full of it.
Pete